- 3 1/2 cups flour
- 1/4 teaspoon salt
- 1 1/4 teaspoons baking powder
- 1 1/4 teaspoons baking soda
- 1 cup unsweetened cocoa powder
- 1/2 cup hot coffee
- 2 cups brown sugar
- 3/4 cup oil
- 1 egg
- 1 teaspoon vanilla
- 1/2 cup buttermilk
To make the cookies: Pre-heat oven to 350ºF. Line cookie sheets with parchment paper.
Whisk together the flour, salt, baking powder and baking soda in a large bowl.
In another large bowl, whisk together the cocoa powder, hot coffee and 1/2 cup hot water until the powder is dissolved.
In a small bowl, combine the brown sugar and oil. Add this to the cocoa mixture and whisk until combined. Add the egg, vanilla and buttermilk and whisk until smooth.
Use a rubber spatula and fold the dry ingredients into the wet ingredients until combined.
Drop the dough by heaping tablespoons 1 inch apart and bake for 10 minutes. The cookies should just start to crack and should still be a little soft. Do not overbake, or they will be too dry.
To make the chocolate ganache: Melt 1/2 cup chocolate chips with 3 tablespoons cream. Stir until smooth and let cool to room temperature.
To make the filling: Whisk the egg whites and sugar together in a medium size bowl and set over a pan of simmering water. Heat the mixture until the sugar is totally dissolved and the color is milky white, 2-3 minutes.
Transfer the egg mixture to the bowl of an electric mixer with the whisk attachment and beat on medium-high until smooth and fluffy, 5 minutes. Remove the whisk attachment and replace with the paddle attachment; add the cubed butter and beat on medium-high speed until the mixture is smooth and fluffy, another 5 minutes. Add the salt and vanilla and beat for 5 seconds.
To assemble the whoopie pies, cool the cookies and turn them upside down (flat side up). Spread about 1 teaspoon chocolate ganache on one cookie. Spread about 1 tablespoon filling on another cookie and sandwich the two cookies together. Continue with the rest of the cookies. Store in the refrigerator for up to three days. Let the whoopie pies come to room temperature before serving.