Adapted from Brown Eyed Baker
3 cups flour
1/3 cup unsweented cocoa powder
1 teaspoon baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1/2 cup butter, softened
1/2 cup vegetable shortening
1 cup packed light brown sugar
1/2 cup sugar
2 teaspoons vanilla
3 teaspoons liquid red food colouring
1 cup milk
1 tablespoon lemon juice
1/2 cup cream cheese, softened
1/4 cup butter, softened
1 teaspoon vanilla
3 1/2 cups icing sugar
1. Preheat oven to 350ºF and line baking sheets with parchment paper. In a small bowl mix together milk and lemon juice, let stand until needed. In a large bowl whisk together flour, cocoa powder, baking powder, baking soda, and salt. Set aside.
2. In another large bowl cream together butter and shortening until light and fluffy. Blend in eggs, one at a time, until incorporated. On low speed blend in vanilla and food colouring.
3. Add half of the dry ingrdients to wet ingredients along with half of the soured milk. Blend in remaining flour and milk until smooth batter forms.
4. Drop batter by tablespoonfuls onto baking sheet, spacing about 2" apart. I baked 6 at a time on my baking sheet. Bake for about 10-12 minutes until just firm on top and toothpick comes out clean. Let cool on pan 3 minutes before transfering to wire rack to cool completely.
5. For the filling, in a large bowl cream together cream cheese, butter, and vanilla until smooth. Gradually blend in icing sugar. Spoon into piping bag fitted with #12 tip or into sandwich bag with corner cut off.
6. Squeeze some filling onto the bottom center of one cookie then sandwich together with another to make your whoopie pies! Serve & enjoy!
Makes about 20 assembled whoopie pies. Store in airtight container, separating layers with baking paper.