Up until last month, I'd never had a whoopie pie. I knew what they were - cakey cookies sandwiched with filling - but I'd never made them before. Maybe it was because I didn't think cookies should be cakey. We all know how I feel about that subject. Maybe because I thought the name was silly - it's a pie? It's a cookie? It's whoopie? Okay, I get odd notions sometimes. In any case, whoopie pies were not in my every day baking arsenal.
However, last month, I made the Spiced Pumpkin Cookie Cakes which were essentially pumpkin whoopie pies. Those turned out pretty well so I was a bit more broad-minded when I saw this recipe for peanut butter whoopie pies from Martha Stewart's Cookies book. It was the same concept - cakey chocolate "cookies" with peanut butter filling. The main selling point though was it used 2 cups of buttermilk and I had a pint to use up this week before the expiration date so it seemed like a good opportunity to make whoopie (yeah, you know I had to get a bad pun in)....pies.
These turned out really well. The batter is softer than a cookie dough but more firm than cake or brownie batter. I used two spoons to shape the blob of cookie dough/batter back and forth before dropping onto a parchment-lined cookie sheet. I made the blobs fairly smooth and they smoothed out even further and baked into thick, puffy cookie-like shapes. I wouldn't call them cookies though since they had the texture and softness of a little cake. Definitely only bake these for 8 minutes as that's long enough to give them a nice, moist texture without being raw or dry. I only made half the peanut butter filling recipe since I tend to go light on fillings and knew a full recipe would be too much. I ended up a little short but I sandwiched the remaining cookies with dulce de leche that my friend Jenny brought back for me from South America. Heaven. Instead of cookies or "pie", think of these as little chocolate cakes sandwiched with peanut butter filling. Regardless of the nomenclature, they go down really well and look nice too.
Cookies
3 ½ cups all-purpose flour
1 ½ cups unsweetened cocoa powder (I used 1 cup Pernigotti cocoa and ½ cup Hershey’s cocoa)
1 tablespoon baking soda
1 teaspoon baking powder
1 teaspoon salt
2 sticks (1 cup) unsalted butter, room temperature
2 cups sugar
2 large eggs
2 cups buttermilk, room temperature
2 teaspoons pure vanilla extract
Filling
1 1/3 cup natural creamy peanut butter
1 cup (2 sticks) butter
1 ½ cups confectioners’ sugar
Coarse salt, optional
1. Preheat oven to 400˚F. Line two baking sheets with parchment paper. Sift together flour, cocoa powder, baking soda, baking powder and salt. With an electric mixer, beat butter and sugar on medium speed until light and fluffy. Add eggs, buttermilk and vanilla. Beat until well combined. On low speed, slowly add dry ingredients, mix until combined.
2. Drop 1 ½ tablespoons of batter onto prepared baking sheets, spacing 2 inches apart. Bake until set, about 8 minutes, rotating halfway through. Do not overbake. Cool completely on a wire rack.
3. Make filling: With an electric mixer, beat peanut butter and butter on high speed until smooth. Reduce speed to low. Add confectioners’ sugar; mix until combined. Raise speed to high and mix until fluffy and smooth, about 3 minutes. Season with salt, if desired.