1.Preheat the oven to 350F (180C).
2.In a big mixing bowl, beat the butter and sugar until the color turns light and the consistency gets fluffy.
3.Then add the egg, vanilla extract, and butter milk. Continue to mix with a whisk.
4.Sift the flour, cocoa powder, baking powder and salt.
5.Add the dry ingredients to the wet ingredients. Stir with a spatula. (The consistency won’t be very thick.)
6.Divide the batter into two bowls. Add red color into one bowl and add blue one to the other bowl.
7.Rest the batter in the fridge for 10 minutes.
8.Take one scoop of dough and place it on the tray.
9.Have equal cake batter of both colors because they will overlap each other.
10.Flatten the dough by pressing lightly with your hand.
11.Bake in the oven at 180/350F degrees for 8-10 minutes
12.Allow to cool after removing from oven.
13.While the cakes are cooling, in a large bowl, whisk together the butter, marshmallow fluff, powdered sugar, and vanilla extract.
14.After it reaches a homogeneous consistency, take it into a squeezing bag and squeeze it between the cakes and cover the other cake on it.
15.Whoopie pies are ready, ENJOY