banana cupcakes with peanut butter buttercream

Ahh, the horror!  As I was sitting down to wax poetic about these monkey-worthy cupcakes, the tiniest of spiders scurried across the top of my laptop.  I blame the new seven foot Oregon pine tree draped with glittering white lights standing in the corner of my living room.  Now, I am completely incapable of focusing on buttercream.  Thanks a lot, Mr. Tiny Spider.

Thankfully, my apartment was arachnid-free this afternoon when I had a few spare moments to aimlessly flip through the pages of some of my cookbooks.  I was looking for a way to satisfy my sweet tooth without braving the post-holiday, Sunday shopper frenzy that is the market by my apartment.  Peanut butter buttercream is one of the most addictive things going in my kitchen at the moment, and we had no problem scraping out every last bit to clean the bowl — Karen DeMasco deserves an award.  The recipe was simple but these cupcakes and frosting yielded such satisfying flavors and textures that they are already packed up and are ready to be foisted upon my coworkers.  Ripe, mashed bananas add color, moisture and deep flavor to the cupcakes, which can so often be dry and dull.  They also scored major points with me because they require little more than pantry staples, are the perfect rainy day activity and stay fresh for a couple of days at room temperature.  I cannot wait to make these again.

banana cupcakes with peanut butter buttercream
adapted from The Craft of Baking
yields one dozen cupcakes

For the cupcakes:
3/4c sugar
1/3c plus 2T vegetable oil
3/4c mashed bananas
1 large egg
1 large egg yolk
1/3c plus 2T buttermilk
3/4t vanilla extract
1c plus 2T unbleached all purpose flour
3/4t baking soda
1/2t kosher salt

For the buttercream:
2 large egg whites
1/4c sugar
8T unsalted butter, at room temperature
1/4c creamy peanut butter
1/4t vanilla extract
1/4t kosher salt

For the cupcakes:
Preheat the oven to 350 degrees. Line a 12-cup muffin tin with paper liners.

In a large bowl, sift together the flour, baking soda and salt. In a medium bowl, whisk the sugar and oil. Add the mashed bananas, egg, egg yolk, buttermilk and vanilla. Pour the wet ingredients on the dry ingredients and mix together. Fill each muffin cup 3/4 full with the batter.* Bake for 20-22 minutes until a toothpick inserted in the middle comes out clean. Quickly remove the cupcakes from the tin and and cool right side up on a cooling rack.

For the buttercream:
In the bowl of an electric mixer add the sugar and egg whites. Beat with a wire whisk by hand for 2 minutes until the mixture starts to get frothy. Place the bowl atop a medium saucepan of simmering water to create a double boiler. Whisk constantly for 3 minutes until the mixture is warm to the touch. Put the bowl on the electric mixer fixed with the wire whisk and beat on medium for 5 minutes until the mixture becomes shiny and forms a soft peak.

With the machine running, add the butter one small piece at a time, letting the butter incorporate after each addition. Turn the speed to medium-high and add the peanut butter, salt and vanilla extract. Beat for 10 minutes until the buttercream becomes shiny and creamy. Spread the buttercream over the top of the cupcakes.**

*At first, I used my traditional method of scooping the batter into the cups with my ice cream scoop. This put too much batter into the cups and I ended up evening them out in order to make 12 cupcakes.
**I was worried there would not be enough frosting to pipe over the cupcakes, so I opted for the old fashioned application.  This made plenty, plenty of frosting and I wish I had dug out the piping bag and tip.