Classic Whoopie Pies

I’ve been going around and finding whoopie pies at bakeries in London and rating them so I decided that I should make my own and see how I did before I started critiquing the efforts of others. I decided to make a classic whoopie pie (chocolate cake and a light almost marshmallow filling).
I was pretty pleased with the end result! The cake was light and moist and the filling is different to what’s usually on a cupcake. It’s light but not gooey and I think it has the flavor of ice cream almost. I adapted this recipe from the NY Times. It took me awhile to find a recipe that didn’t use Marshmallow Fluff or Corn Syrup (both which you don’t get on a regular basis in the UK). I was also really pleased I found a cake recipe that didn’t have vegetable shortening. I don’t particularly like the way it tastes.

Cake

½ cup of unsalted butter at room temperature
1 cup light brown sugar
1 large egg
1 tsp vanilla extract
1 ¼ tsp baking soda
1 tsp salt
2 cups all-purpose flour
½ cup cocoa
1 cup buttermilk (I used 1 cup soy milk with 1 tbs apple cider vinegar)

Filling

3 large egg whites
¾ cup sugar
1 cup unsalted butter at room temperature
¾ tsp vanilla
¼ tsp sea salt

For the Cake

1. Preheat oven to 350 F/180 C. In a mixing bowl, cream together the butter and brown sugar. Add the egg and vanilla extract and beat until light and creamy. In a separate bowl, whisk together the baking soda, salt, flour and cocoa. Add dry ingredients to butter mixture in three parts, alternating with buttermilk, and combining well after each addition.

The batter at the end should be light and look a little fudgey
2. Spoon 1/4-cup mounds of batter on the baking sheet. I used a small greased non stick baking sheet with and spooned 6 pies on each. Bake until tops are puffed and cakes spring back when touched, 12 to 14 minutes. Remove from oven and cool completely before filling.
I forgot to take a picture before they were baked, but I put 6 mounds on each baking sheet so they had room to expand and rise
For the Filling
1. This part can be a bit tricky. Set up a double boiler (medium sized pan with 2 inches of boiling water on high heat with a metal bowl placed on top). In the metal bowl combine egg whites and sugar. Place over simmering water and whisk just until sugar is dissolved and temperature reaches 180 degrees on an instant-read thermometer (this can take a few minutes).
4. Using a whisk attachment on an electric mixer, whisk egg whites and sugar on high until they double in volume and become thick and shiny (it will look like marshmallow) about 5-8 minutes. Continue to whisk until cool. Reduce speed to medium and begin to add butter about 1/2 tablespoon at a time, until all the butter is incorporated. Add vanilla and salt. For best result use immediately or place in an airtight container and chill for up to 3 days, whisking buttercream again before using.
The thermometer I had is quite big so I balanced it against the wall
This is how it should look before the butter is whisked in (almost like marshmallow)

5. To put together use a spatula, place ¼ cup filling on the flat side of each of 6 cakes, spreading it to edges (I tired to pipe it on to make it look neater but the consistency isn’t right). Place a cake piece gently on top of each. Store in an airtight container at room temperature for up to 3 days, or wrap individually and freeze for up to 3 months.

If you don’t have a thermometer or don’t want to make the marshmallow filling the Vanilla Frosting from the Easter Egg Cupcakes would be a good substitute.

Mine made about 10 pies

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