A favorite childhood snack is now back as a favorite cake flavor. I’ll admit, it sounds a bit out there. Peanut butter? In a cake? My family was scrunching their noses in skepticism, but I was hopeful. My heart was set on trying something new, something different.
I’ll also admit, it’s not entirely innovative. There are countless PB&J inspired desserts. And this one…this one is a definite winner. The cake is moist and light, even with a heavy component such as peanut butter. Because I’m a nerd, I’m gonna take a quick detour down Science-y Lane.
To achieve the ultimate moistness (Blech who else hates that word), in a cake specifically, there has to be a precise amount between the two main types of fat: liquid and solid. Fat functions as a flavor, a leavener, a strengthener and a tenderizer. At least one type of fat is required in every baked good- otherwise, they’ll be dry, crumbly and probably lacking in flavor.
In this recipe specifically, there are five fatty ingredients: solid butter, peanut butter, sour cream, eggs and buttermilk. That is a lot of fat. But the liquid-ness (?) of each ingredient varies greatly! That is what leads to the ultimate moisture content (that’s a better way to put it, I think).
Because each fat is a different texture, the ratios are more important than ever. The peanut butter is extremely drying. The first batch I made I used equal parts of butter and PB, with 1/3 cup buttermilk and 1/4 cup sour cream. I baked it for exactly 20 minutes, just starting to brown on top. It was most definitely not over baked, but still came out very dry. The taste was there; it was absolutely delicious but the texture wasn’t right. I knew after the first taste that the liquid fat content would need to be bumped up, at least a decent amount. I started with the buttermilk because with the acidic buttermilk, the basic baking soda needed to be adjusted as well. The sour cream also needed to be increased, which also affects the amount of baking soda needed (are you still here…?)
Science-y Lane story short, the amount of liquid fat needed to be more than the amount of the peanut butter. The ratio below is the perfect mix of liquid to solid, without skimping on the flavor!
One more thing before the goodness of the recipe: If you follow me on Instagram, you’ll probably know that on Thursday I participated in my very first Cake Collab, the #monthlycolorcollab hosted by @ww_bakes. Most of you who know me will be surprised to see that the first collab I did was for a purple cake. Normally, I can’t stand purple. Despite the popular opinion that I only like black, I do love an array of colors. Just not purple…usually. I decided to participate in the Purple Collab for my mother. My mother, an avid peanut butter fan, inspired me to settle on the flavor combo, and so this recipe was born. This coming weekend was supposed to be her Spartan Ultra challenge, but due to COVID-19, it has been cancelled. This cake was supposed to have a stenciled Spartan Ultra logo, however I opted for a victory flower boquet. (Stay tuned later on for keto-friendly cookie recipe with the Spartan logo.)
Anyway, my point is, peanut butter and jelly is now a cake, science is important, and my mom is a Spartan. Enjoy!