- 1/2 stick (4 tablespoons) unsalted butter, at room temperature
- 4 tablespoons vegetable shortening
- 1 1/4 teaspoons pure vanilla extract
- 1-1 1/2 cups confectioner's sugar
- 1 recipe Chocolate Wafer Cookies
- In a large bowl, mix the butter, shortening, and vanilla until well blended. Add the first 1 cup of confectioner's sugar and stir until the sugar is incorporated completely into the butter mixture. The filling should be thick and stiff. Add more confectioner's sugar, one tablespoon at a time, to reach the desired consistency.
- Place one-half of the chocolate wafer cookies upside down on a level surface. Divide the filling among the cookies and flatten with wet hands or a spoon. Place the other half of the cookies right side up on top of the filling and press down gently to create sandwich cookies.