Peanut Butter Fudge Cake (2024)

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September 12, 2013 (updated Sep 13, 2016) by Jennifer McHenry //

34 Comments

Oh, peanut butter and chocolate, how I love you. Seriously, I never seem to get tired of that classic combination. I’ve used that famous duo in cookies, cheesecake, cake, brownies, pie, and more. And, I don’t plan on stopping any time soon.

If you follow my baking adventures, you know that I’m not much on pretty, elaborate desserts. I may make something like that occasionally, but my practical side says that simple is the way to go more often than not. I’m betting most of you are with me on that, too.

This cake is one of those lovely one-layer kind. It’s made very much like a Texas Sheet Cake, with some cooking on the stovetop for both the cake and the icing. The chocolate cake is moist and dense and just lovely. It has a nice, delicate chocolate flavor. That’s a good thing, because the icing is not even remotely subtle in the chocolate department.

The peanut butter filling couldn’t be simpler. It’s peanut butter. Seriously. Spread it on the cake while it’s still warm, and the peanut butter will make a lovely, tasty layer between the cake and the icing.

I love this kind of icing. It’s simple to make, so that’s always a plus. And, it’s so soft and gooey. It goes on the cake while it’s warm, and then it hardens and sets as it cools. It forms some kind of serious shield over the cake. Don’t be alarmed if the icing cracks and crinkles when you cut into it. That’s just the nature of this kind of icing. If it bothers you, that’s why some very smart person invented garnishes. Maybe some chopped peanut butter cups?

This cake is what’s known as a crowd-pleaser. First of all, it makes enough for a crowd. Secondly, it’s chocolate and peanut butter, so what’s not to like?

As is always the case when chocolate is the center of attention, be sure to use a good quality cocoa powder for the best results. I used one of my favorites, Scharffen Berger unsweetened natural cocoa powder.

I made this cake to help out my blogging friend Erin of The Spiffy Cookie. She is finishing up her dissertation and asked for a little help from some fellow food bloggers.

Click here for the recipe.

cakes, chocolate, frostings, one-layer cakes

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34 Comments on “Peanut Butter Fudge Cake”

Kayle (The Cooking Actress) September 12, 2013 @ 12:04 pm Reply

yessssssssssssssssssss-so happy you posted this on Spiffy Cookie! LOOVE
becca @ Crumbs September 12, 2013 @ 2:33 pm Reply
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my oh my these look good! peanut butter and chocolate is a favourite combination of mine too!
Amanda @ Once Upon a Recipe September 12, 2013 @ 4:49 pm Reply

Ermagerd. This cake! I’d just love to sink my teeth into a big fat slice. How decadent!
JEP September 12, 2013 @ 5:18 pm Reply

This cake will be perfect in every way. I cannot imagine a better tasting cake than this one:)
marcie @ Flavor the Moments September 12, 2013 @ 6:47 pm Reply

This looks like the perfect cake creation, because I love peanut butter and chocolate!
Tracy {pale yellow} September 12, 2013 @ 7:00 pm Reply

Oh my! This looks fantastic, I can’t wait to make one for myself!
Joanne September 12, 2013 @ 10:15 pm Reply

Peanut butter and chocolate always always always sounds good to me! Love that layer of icing!
Kathy September 12, 2013 @ 11:14 pm Reply

I will never get tired of peanut butter and chocolate either! So good. This cake looks incredible. Love the layered frostings!
Catherine September 14, 2013 @ 1:47 pm Reply

Wow – this looks incredible! I can eat a whole tub of peanut butter by itself but added to chocolate cake, I die! This discovery is not going to do my waistline any favours! x
Kristi @ My San Francisco Kitchen September 15, 2013 @ 12:06 am Reply

Peanut butter + chocolate = heaven! Looks so good 🙂
Shelly (Cookies and Cups) September 15, 2013 @ 5:48 pm Reply

This looks so good! Peanut butter and fudge go along so well =)
Christina R September 19, 2013 @ 6:46 pm Reply

I made this cake last night, and I have to say, it’s the BEST fudge cake in the world! So decadent and rich, you only an eat a small square at a time. Tastes like a layer of homemade fudge on top of rich chocolate cake…I actually swirled the top icing a bit, and as it set it actually did look like a huge block of homemade fudge…so much so that when my husband cut into it he said,”oh, there’s cake underneath!”
Stephanie @ PlainChicken September 25, 2013 @ 12:07 pm Reply
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Chocolate Truffle Fudge - Briana Thomas

I am making this next week. I LOVE peanut butter and chocolate. This looks like heaven!
Melissa @ My Recent Favorite books October 4, 2013 @ 11:08 am Reply

My 2 favorite flavor combinations! sounds yummy!
stacie sperlazza January 15, 2014 @ 2:08 pm Reply

I like it
stacie sperlazza January 15, 2014 @ 2:09 pm Reply

I like it it looks good
Adrian Bates January 17, 2014 @ 9:32 am Reply

I made this cake about 20 years ago.
Adrian Bates January 17, 2014 @ 9:33 am Reply

I made 2 versions of this cake
David January 19, 2014 @ 4:50 pm Reply

When making the cake, it seemed that the egg started to cook when you added it to the butter, coca, buttermilk and water and then brought that to a boil. Is this the way it should be or am I doing something wrong? When I pulled the cake out of the oven, it looks normal, but there were definitely small pieces of cooked egg in the batter. Thanks for any help you can give.
- Lisa February 23, 2014 @ 10:22 am Reply
  
  We were wondering the same thing! Weird.
  - Jennifer McHenry February 23, 2014 @ 10:49 am Reply
    
    Hi, David and Lisa! I didn’t have that problem, but I think the key is the constant stirring.
- Michelle March 18, 2016 @ 10:19 pm Reply
  
  I had the same problem, too. When I got to that step I knew it might be an issue (eggs into hot batter not a good idea!) so I stired like mad. It didn’t help, still lots of cooked egg lumps. I was able to pick out most of them, but still saw them on pieces friends were eating. If they noticed they didn’t say anything.
  - Patty January 10, 2019 @ 9:51 am Reply
    
    I make this quite a bit for my family and I didn’t like that part either, so I make it now with a homemade egg substitute (1 heaping tsp cornstarch mixed into 1/4 cup of water equals one egg) and have had wonderful success with it.
- Mary Pearl October 25, 2021 @ 12:29 pm Reply
  
  I noticed the same thing., even with constant stirring. If you add the egg when you add the vanilla it won’t do that. Looking forward to trying this cake. I’m making it for my husband’s birthday.
Lorraine January 19, 2014 @ 9:17 pm Reply

Made this tonight and it turned out delicious. Will definitely make this again…over and over 🙂
Jana Frei February 26, 2014 @ 9:20 pm Reply

The recipe did not say how much baking soda to add to the flour and sugar mixture. How much?
- Jennifer McHenry February 26, 2014 @ 10:10 pm Reply
  
  Jana, it’s listed in the ingredients – 1 teaspoon.
Kristin felts March 6, 2014 @ 8:07 pm Reply

I had the problem with the egg cooking as well, and I was constantly stirring it. I think maybe it heated too quickly. Despite the chewy but here and there the cake was delicious. I think I will cut the peanut butter in half next time. It was a bit much.
- Sarah January 23, 2015 @ 4:22 pm Reply
  
  Hey Kristin, a trick in baking that I have learned is break the eggs in a separate bowl and add a little of the hot mixture to the eggs while stirring constantly. This helps bring the eggs to the same temp as the hot mixture without cooking the eggs. Makes it easier to mix the eggs into the hot mixture.
Sandy B November 3, 2014 @ 8:25 pm Reply

So glad I found your site. I love baking……just retired from work & so excited to start baking for my family & friends.
- Jennifer McHenry November 4, 2014 @ 4:19 pm Reply
  
  Welcome, Sandy! I hope you find plenty of new favorite recipes!
Rachel March 5, 2015 @ 2:25 pm Reply

Oh, how I love this combination, peanut butter and chocolate.
Shirley February 3, 2021 @ 4:50 pm Reply

Will it be just as yummy if I used 2% milk instead of buttermilk?
- Jennifer McHenry February 4, 2021 @ 10:54 am Reply
  
  Hi, Shirley. I’ve got some good suggestions here: Buttermilk Substitutes in Baking.

FAQs

Why did my peanut butter fudge not get hard? ›

Fudge Didn't Set

If your fudge turned out super sticky, or it didn't set as it cooled, it probably never got hot enough. This mistake is super easy to avoid if you use a candy thermometer and cook the fudge to the temperature specified in the recipe (usually between 234 and 239°F).

What to do with failed fudge? ›

OPTION 1) Depending on how runny it is, you can either use it as a frosting for cakes, or a sauce for ice-cream. OPTION 2) Freeze it overnight. Cut it into squares. Cover each square thickly in melted chocolate, ensuring no part of the fudge is exposed.

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What is the secret to smooth fudge that is not gritty? ›

Once a seed crystal forms, it grows bigger and bigger as the fudge cools. A lot of big crystals in fudge makes it grainy. By letting the fudge cool without stirring, you avoid creating seed crystals.

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What makes fudge moist? ›

If there is too much evaporation, when the cooking time is too long, there will not be enough water left in the fudge and it will be too hard. Conversely, if the cooking time is too brief and there is not enough evaporation, too much water will remain and the fudge will be too soft.

Get More Info ›

Why is my fudge not creamy? ›

Beating the mixture encourages the formation of small sugar crystals, which leads to the crumbly texture. The crystals may not be noticeable in themselves but the fudge mixture will thicken and turn from shiny to matte in appearance.

Show Me More ›

Why is my peanut butter fudge dry and crumbly? ›

Follow the recipe to a tee when cooking the sugar

However, it's important to bring the sugar to the exact right temperature. If it doesn't boil, your fudge will end up too mushy, and if it cooks for too long, you'll end up with a dry, crumbly mess.

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How do you fix runny peanut butter fudge? ›

Bring the fudge back to a boil with 1–2 US tbsp (15–30 ml) of cream. If your fudge is soft or runny, it probably didn't come up to a high enough temperature while it was cooking. Put it back into the saucepan and add 1–2 US tbsp (15–30 ml) of 35% fat whipping cream.

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Why won't my 3 ingredient condensed milk fudge set? ›

Why won't my 3 ingredient fudge set? This often happens when the condensed milk and chocolate chip mixture isn't hot enough to start. Everything must be completely melted before it is transferred to the pan to cool.

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How to rescue fudge that won't set? ›

How can you fix soft fudge? Put it in a microwave safe bowl that is large enough that it won't boil over. Reheat it to the boiling point and cook for about 3 more minutes. Then you can beat some powdered sugar into it if this doesn't make it set.

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How to fix grainy peanut butter fudge? ›

The solution? A fudge do-over. Even though it set up properly, I threw it back into a saucepan with about 1 1/2 cups of water and gently heated the mixture to dissolve the fudge into the water. From there, I pretty much re-did the whole cooking process.

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What happens if you cook fudge too long? ›

Too cooked

The result is hard and brittle fudge. To save the fudge, put it in a saucepan with 45 to 60 ml (3 or 4 tbsp.) of 35% cream and bring to a boil, stirring until the sugar is completely melted. Then let it boil without stirring until the thermometer reaches 114 to 115 °C (237 to 239 °F).

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Why did my fudge turn out like taffy? ›

If the temperature is too low, the fudge will be too soft and sticky, and if it's too high, it will turn into a hard, crumbly mess. The ideal temperature to cook fudge is between 232-234 degrees F (111-112 degrees C).

Do you stir fudge when it's boiling? ›

Know When and When NOT to Stir

Stir the ingredients to dissolve the sugar until the mixture comes to a boil. If your recipe uses milk, stirring will keep the mixture from curdling. But once it reaches about 236–238 degrees F/113–114 degrees C (the "soft-ball" stage), do not stir it or even shake the pan.

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What gives fudge its firm texture? ›

The key to creamy, luscious fudge is controlling crystal formation. If the sucrose (table sugar) crystals are small, the fudge will feel creamy and smooth on your tongue. But if the crystals are large, the fudge develops a crumbly, dry, or even coarse texture.

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What does cream of tartar do in fudge? ›

Cream of tartar is used in caramel sauces and fudge to help prevent the sugar from crystallizing while cooking. It also prevents cooling sugars from forming brittle crystals, this is why it's the secret ingredient in snickerdoodles!

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How do you cut fudge so it doesn't crumble? ›

Put both knives into a large measuring cup, add boiling water onto the knives, and before cutting the chocolate or the dessert into pieces, wipe the knife with a towel. The warm knife will easily cut through without cracking.