Things that I learned while making these cupcakes: Adding Black Raspberry Puree to Butter Cream does not produce a nice mellow, purplish pink color that I had hoped …. more this lovely Bubble Gum color. Lesson learned. So, while these are the least attractive cupcakes that I have made in a long time, it’s the thought that counts. Happy Birthday to my Roommate!
for the chocolate cupcakes
4 1/2 ounces high-quality bittersweet chocolate, finely chopped
9 tablespoons (1 stick plus 1 tablespoon) unsalted butter, room temperature
1 cup confectioners’ sugar
6 large eggs, separated, at room temperature
1 teaspoon vanilla extract
1/2 cup granulated sugar
1 cup all-purpose flour
For the black raspberry puree filling
1 pint blackberries (or black raspberries, if you can find them)
2 pints raspberries
juice from 1/2 a lemon
1 tablespoon cornstarch mixed with 2 tablespoons cold water
for the raspberry butter cream frosting
1 cup (2 sticks) butter, softened to room temperature
1/4 cup vegetable shortening
4 cups powdered sugar
1/2 teaspoon salt
1 teaspoon vanilla
1 teaspoon raspberry extract
1/2 cup raspberry puree
Preheat oven to 400F. Prepare a muffin pan with liners.
In the top part of a double boiler over very hot, but not simmering, water, or in a microwave at medium power, melt the chocolate. Remove from the heat or the oven, and let stand, stirring often, until cool.
Beat the butter in the bowl of a stand mixer fitted with the paddle blade on medium-high speed until smooth, about 1 minute. On low speed, beat in the confectioners’ sugar. Return the speed to medium-high and beat until light in color and texture, about 2 minutes. Beat in the egg yolks, one at a time, scraping down the sides of the bowl. Beat in the chocolate and vanilla.
Beat the egg whites and granulated sugar in a large bowl with an electric mixer on high speed just until they form soft, shiny peaks. Do not overbeat. Stir about one fourth of the beaten whites into the chocolate mixture to lighten it, then fold in the remaining whites, leaving a few visible wisps of whites. Sift half of the flour over the chocolate mixture, and fold in with a rubber spatula. Repeat with the remaining flour.
Fill the lined muffin cups three-quarters full, being careful not to overfill. Bake until a toothpick inserted in the center of the cupcake comes out clean, about 20-22 minutes. Cool the cupcakes in the pan for 5 minutes, then transfer to a wire rack to cool completely.
While the cupcakes are baking, start your puree for the filling. In a saucepan over medium heat, combine black berries, 1 pint of the raspberries, the sugar and the lemon juice. Bring to a boil and then simmer lightly for about 5-6 minutes, until the berries are pretty much disintegrated. Pour through a fine mesh sieve and push on the solids until you basically just have the seeds like in the sieve. Discard the seeds and any remaining pulp that didn’t make it through the sieve. Return the mixture to the saucepan and heat until just boiling. Add the corn starch slurry and let come to a full boil so the puree thickens. Divide the puree into two work bowls or measuring cups. You will need 1/2 cup for the frosting. With the remaining, add the other pint of raspberries. Both should be completely cool before proceeding.
Once the cupcakes are done baking, and everything has cooled completely, make your frosting. In the bowl of a stand mixer, cream together butter and shortening. Slowly add in powdered sugar 1 cup at a time. Blend in salt and extracts. Stir in raspberry puree and continue to mix until your butter cream is smooth and is piping consistency. Keep chilled in the refrigerator while you fill the cupcakes.
To assemble and decorate: Insert a small knife at a 45 degree angle about 1/8 inch from the edge of each cupcake and cut all the way around, remove a cone of cake (or use a cupcake corer, if you have one). Cut away all but the top 1/4 inch of the cone; leaving only a small disk of cake which will be used to top the cupcake. With a small spoon, pour in 2 tablespoons of the raspberry puree with whole raspberries into the hole and then top with the disk. Pipe a generous amount of frosting on each cupcake. Garnish as you like with a raspberry, sprinkles, etc.
Keep refrigerated until ready to serve.