July 4, 2014 – In more than 16 years in the United States I had never eaten nor made whoopie pies. The 4th of July seemed an appropriate occasion to try them.
Two personal taste obstacles though. I am not a fan of shortening and avoid it whenever I can substitute real butter. For the filling German buttercream seemed a good option but one of the reasons why I am not a fan of it neither is that it is often so hard and stiff that it crumbles.
Replacing the shortening in the original recipe was easy and the dough came out great. I also used less sugar than the original recipe called for (1 cup instead of 1½ cups). Tweaking the buttercream was a bit trickier. I do not make buttercream often and wasn’t sure how much I needed to make the buttercream just solid enough to spread and not run off. One stick of butter worked just fine to make the filling velvety smooth.
German buttercream is made with custard and butter, and they must both have the same temperature, or else the butter will curdle.
If I make those again, I might add other flavors to the buttercream, such as coffee.
Whoopie Pies with German Buttercream
Adapted from Bertha Sweet’s Whoopie Pie recipe, courtesy of Judy von Feldt.
1 stick (115 g) butter, softened
1 cup (200 g) sugar
1 teaspoon vanilla extract
2½ cups (12.5 ounces/350 g) flour
1 teaspoon baking soda
1 teaspoon baking powder
¼ teaspoon salt
½ cup (40 g) unsweetened cocoa
½ cup (120 ml) hot water
½ cup (120 ml) buttermilk
2 heaping tablespoons cornstarch
2 cups (480 ml) milk (I used 2%)
1 tablespoon vanilla extract
1/3 cup (65) g sugar
4 egg yolks
Pinch of salt
1 stick (115 g) butter, softened
1. Preheat the oven to 350 degrees F (180 degrees C). Line two baking sheets with parchment paper.
2. For the dough cream butter and sugar. Beat together eggs and vanilla and add. Mix flour, baking powder, baking soda and salt and add. Dissolve cocoa in hot water and add, alternating with buttermilk. Stir until smooth.
3. Fill about two-thirds of a pastry bag fitted with a large round tip with dough and squirt about one tablespoon for each cookie onto the lined baking sheet, leaving at least ½ inch distance between them. Bake one baking sheet after the other in the preheated oven for 12 minutes.
4. Transfer the parchment paper with the cookies to a cake rack and let cool completely before carefully removing the cookies. Place them on the cake rack and store in a cool dry place until you are ready to fill them.
5. For the buttercream dissolve the cornstarch in a few tablespoons of the milk. Bring the rest of the milk to a boil. Add the cornstarch, vanilla and sugar and cook until it thickens, stirring constantly.
6. Remove from the heat and add the beaten egg yolks and salt. Whisk to incorporate. Return to the heat and simmer over very low heat until it thickens, stirring constantly. Do not boil, or the eggs will curdle.
7. Remove from the heat and cool to lukewarm. Slowly add the butter, which must have the same temperature. Whisk until smooth. Refrigerate overnight. The buttercream should be fully set.
8. Spread a generous amount of buttercream on a completely cooled cookie and top with another cookie. Place the whoopie pies in an airtight container with layers of wax paper between them. Refrigerate.
Makes 24 pieces