My gluten free peanut butter cake is a moist peanut butter sheet cake topped with a warm fudgy frosting and crunchy salted peanuts ~ it’s just ridiculously good.
My Old Fashioned Peanut Butter Cake is a perennial favorite ~ so many of you say you come back to this recipe again and again for birthdays, holidays, office parties, and everything in-between. It’s so rich and moist we sneak little slivers every time we pass through the kitchen. And now with my new gluten free peanut butter cake nobody has to miss the party! Why is it so good?
SIMPLE SWAP: a 1:1 swap for a GF baking mix is the only change ~ why mess with perfection?
EXTRA TENDER: this cake has an extra tender crumb that might give the original a run for its money.
ONE BOWL, NO MIXER: everything comes together with a whisk and one saucepan. Yes, the cake and the frosting.
THAT FROSTING! It’s cooked on the stovetop and poured hot over the cake, setting up into a soft, rich, almost fudge-like texture that is over-the-top delicious.
gluten free peanut butter cake ingredient notes
The 1:1 gluten free baking mix: if you want the closest texture to wheat flour in your peanut butter sheet cake Cup4Cup wins for tenderness and lightness ~ but King Arthur Measure for Measure or Bob’s Red MillGluten Free 1-to-1 Baking Flour are more budget-friendly and widely available.
The peanut butter: use a regular style creamy peanut butter, I think Jif has the best flavor. Don’t use a ‘natural’ style pb where the oil separates out at the top of the jar.
Buttermilk: buttermilk frostings are traditional in Southern style sheet cakes. Buttermilk adds a little tang that balances the sweetness of this peanut butter cake, while its acidity helps keep the sugar smooth and prevents crystallization
tips and tricks for making a cooked peanut butter frosting
Cooked frostings have a unique fudge-like consistency that makes my gluten free peanut butter cake truly special. There’s nothing tricky here, just follow instructions!
Begin making the frosting just after your cake comes out of the oven
This is the perfect timing so you can pour the hot frosting over the still warm cake.
Use a gentle heat to bring the peanut butter, butter, and buttermilk to a boil
Your buttermilk may split while this frosting cooks. Don’t panic, just continue whisking. Everything will smooth out once the mixture comes to a boil.
If necessary you can keep the finished frosting on a very low heat while you get the cake organized and in position.
Pour the hot frosting immediately over the warm cake in long ribbons
You’re trying to get as much coverage as possible over the cake without spreading because it sets up quickly.
If you do need to spread it a bit, do that quickly and gently.
Preheat oven to 350F and spray a 9×13 pan with nonstick spray.
Whisk together the gluten free baking mix, sugar, baking soda, and salt in a medium bowl and set aside.
Heat the butter and water in a medium/large saucepan until it comes to a boil. Take off the heat and whisk in the peanut butter and oil until smooth. Let cool for a few minutes, then whisk in the eggs, buttermilk, and vanilla until well blended.
Add the dry ingredients to the wet ingredients, and whisk until just combined.
Pour the batter into the prepared pan and bake for 40-45 minutes, until the top is golden and a toothpick inserted in the center comes out clean. Set the cake on a cooling rack while you make the frosting.
To make the frosting, put the butter, peanut butter, and buttermilk in a saucepan and bring to a full boil. Take off the heat and beat in the vanilla and powdered sugar, adding a cup at a time, until the frosting is smooth. I like to put it back on a gentle heat just to rewarm it, stirring constantly, before pouring over the cake. Note: if your frosting is very stiff and not pourable, add a little bit more buttermilk to thin it out.
Pour the hot frosting over the warm cake, working quickly because the frosting sets up immediately. Spread evenly over cake.
Garnish with peanuts.
Your cake will keep at room temperature for a couple of days, but for longer storage refrigerate it.
Notes
Make it chunky! Yes, of course, go ahead and use chunky PB for this cake. I would still use smooth for the frosting, but that’s your call.
Nutritional information is provided as a courtesy and is an estimate only. This information comes from online calculators. Although The View from Great Island attempts to provide accurate nutritional information, these figures are only estimates.
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I was all excited with the email saying “everybody”, but she didn’t mean vegans ugh. Soy milk and acv work great as buttermilk. What are you using for eggs? It seems hit or miss for me with egg subs, so I would love to know if you try this successfully. Thank you.
You might try soy milk plus a touch of lemon juice or vinegar to mimic the buttermilk. For a cup of soy milk you’d use a teaspoon of acid and let it sit for a few minutes before using.
Hey there ~ I'm Sue. I love to make delicious food, photograph it, and write about it, but mostly, I just love to EAT. Isn't that what it's all about? My recipes are creative, vibrant, and totally approachable no matter what your skill level. Let's grab a bite together!
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I love all the new bakes you’re posting lately, right up my street!
I was all excited with the email saying “everybody”, but she didn’t mean vegans ugh. Soy milk and acv work great as buttermilk. What are you using for eggs? It seems hit or miss for me with egg subs, so I would love to know if you try this successfully. Thank you.
I’ll work on a vegan peanut butter cake soon!
Any suggestions for a buttermilk substitute? I have both gluten-free and vegan co-workers. I’ve got the eggs and butter covered.
You might try soy milk plus a touch of lemon juice or vinegar to mimic the buttermilk. For a cup of soy milk you’d use a teaspoon of acid and let it sit for a few minutes before using.
Wow–looks delicious. Any version available with Almond Flour instead of commercial GF (Rice + Gums) substitute?
I don’t have a strictly almond flour version, but it would be worth an experiment.