For chocolate wafers:
• ½ cup unsweetened Dutch process cocoa
• 1 teaspoon baking soda
• ¼ teaspoon baking powder
• 1 cup granulated sugar
• ½ cup + 2 tablespoons (1 ¼ sticks) unsalted butter, room temperature
• 1 large egg
For the filling:
• ¼ cup vegetable shortening
• 2 cups powdered sugar, sifted
• 2 teaspoons vanilla extract
1. Set 2 racks in the middle of the oven. Preheat to 375°F.
2. In a food processor, or bowl of an electric mixer, thoroughly mix the flour, cocoa, baking soda and powder, salt, and sugar. While pulsing, or on low speed, add the butter, and then the egg. Continue processing or mixing until dough comes together in a mass.