-
1
Make Cake Rounds:
-
2
Preheat oven to 350u00b0F with racks in upper and lower third. Line two baking sheets with parchment paper.
-
3
Whisk together flour, cocoa powder, baking soda, and salt in a bowl.
-
4
Beat butter, oil, and sugar with an electric mixer until combined well, about 2 minutes. Beat in egg, vanilla, and vinegar.
-
5
Reduce speed to low and alternately mix in flour and buttermilk in batches, beginning and ending with the flour until combined.
-
6
Add the red food coloring and mix on low speed until thoroughly combined.
-
7
Spoon 2 tablespoon mounds of batter 2-inches apart on lined baking sheets.
-
8
Bake, switching positions of baking sheets halfway through baking, until rounds are puffed and set, 8 to 10 minutes.
-
9
Slide parchment with rounds onto wire racks to cool completely.
-
10
Make Filling:
-
11
Beat together cream cheese, butter, lemon juice, vanilla, salt, and sugar until creamy, 1 to 2 minutes. Spread about 2 tablespoons of filling on flat-side of half the rounds; top with remaining rounds, flat side down, to form whoopie pies.
-
12
To get perfectly round whoopie pies, use a 2 tablespoon ice cream scoop with the cake batter.
-
13
Store whoopie pies, chilled, in an airtight container, the layers separated between sheets of parchment paper, for up to 3 days. Bring to room temperature
