What do you do when your friend travels thousand of miles to see you the week after her birthday? If you said, “Make her a Peanut Butter S’mores Cake,” you would be correct. If you said make her earn the cake by hand modeling, you would be correct and also smart.
My friend Cat was here for her birthday last year as well, so this is the second cake in a row that she’s gotten a cake from me. The only difference is that last year, I let her pick the flavor. Cat is obsessed with Taro Milk Boba Tea, and so we attempted to make cupcakes that somewhat resembled the drink. However, we couldn’t find taro powder, so we ended up using taro root. She also wanted the boba baked into the cupcakes. Unfortunately, we ended up with a dense chewy cake that tasted like potatoes and rock hard boba in the center. Needless to say, these cupcakes never made it to the blog.
Let’s talk about this year’s cake instead, shall we? It was a rousing success. Chocolate buttermilk cake topped with peanut butter swiss meringue buttercream (aka heaven), a chocolate ganache drizzle, graham crackers, and toasted marshmallow meringue. There’s pretty much nothing that could go wrong this year. It’s also a 6-inch cake which is just perfect for a small group, although Cat has a superhuman sugar tolerance and ate about 2/3 of it by herself.
Even though I loved this cake, if I had to make it over again, I would double the amount of marshmallow topping so that it would cover the entire top of the cake. More toasted marshmallow = more better. Also, the peanut butter swiss buttercream makes a crap ton (this is a real measurement), but I like to have extra frosting to get a really smooth finish. Swiss buttercream is also kind of a pain to make in small batches but luckily it freezes beautifully.
The marshmallow topping will hold up at room temperature for 2-3 days. After that, it starts to droop. I would not recommend refrigerating this cake because the marshmallow topping will deflate.