Raspberry Lemon Cupcakes #FarmersMarketWeek

Instructions

For the cake:

1. Preheat the oven to 350 degrees. Line two 12-cup muffin tins with paper liners. Set aside. 
2. In a large measuring cup, whisk together the eggs, egg yolks, 3 tablespoons of the buttermilk and vanilla.
3. Whisk together the flour, sugar, baking powder and salt in the bowl of your standing mixer. Using the paddle attachment, beat in the butter, oil, and remaining buttermilk on low speed until the dry ingredients are moistened, then crank it up to medium speed and beat for 1 ½ minutes. Scrape down the bowl. Add one third of the egg mixture, and beat for about 20 seconds, and scrape the bowl again. Repeat two more times until all the egg mixture is incorporated and the batter is smooth.
4. In a cold bowl with cold beaters, whip the cream to just beyond soft peaks. Stir a quarter of the whipped cream into the batter to lighten it, then carefully fold in the remaining cream.
5. Portion the batter into the prepared pans, filling each well about ⅔ full. Bake until the center of each cupcake springs back when touched and a toothpick comes out clean but moist, about 17-20 minutes. Do not overbake. Cool the cupcakes in the tins on a wire rack for 10 minutes before removing them from the pans to a wire rack to cool completely before filling and frosting.

For the lemon curd filling:

1. In a large mixing bowl, whisk together ⅓ cup of the sugar with the cornstarch.
2. Set the mixing bowl over a saucepan of boiling water, add the lemon juice and zest, and bring the mixture to a boil.
3. In a separate mixing bowl, whisk together the eggs, egg yolks, and the remaining ⅓ cup of sugar.
4. Very slowly pour the hot lemon juice/sugar mixture into the egg mixture, whisking constantly. Once the two are completely combined, pour everything back into the first mixing bowl.
5. Lower the heat under the double boiler to medium, and continue cooking the curd, whisking constantly, until the mixture thickens.
6. Remove from the heat. Pour through a fine-mesh sieve into a clean mixing bowl, pressing down on the mixture to get it all through. Scrape the curd from the bottom of the strainer into the mixing bowl. Discard the solids left in the strainer.
7. Add the butter, 1 tablespoonful at a time, stirring until the butter is completely incorporated before adding the next tablespoonful.
8. Place a sheet of plastic wrap directly on the curd, and refrigerate until completely chilled. The curd will continue to thicken as it cools.

For the raspberry puree:

1. Place the raspberries and sugar in a blender. Puree until smooth. 
2. Pour the puree through a fine-mesh sieve set over a mixing bowl. Use a spatula to force the liquid through the sieve until all that remains is the raspberry seeds. Remember to scrape any juices clinging to the underside of the sieve into the bowl. Discard the solids in the sieve. 
3. Store in the refrigerator until ready to use.

For the buttercream:

1. In a mixing bowl, beat the butter until smooth and creamy and set aside in a cool place.
2. Have ready a heatproof glass measure near the stovetop. In a small heavy saucepan, heat ¾ cup of the sugar and the water, stirring constantly until the sugar dissolves and the mixture is bubbling. Stop stirring and reduce the heat to low.
3. In another mixing bowl, beat the egg whites until foamy, add the cream of tartar, and beat until soft peaks form. Gradually beat in the remaining ¼ cup sugar until stiff peaks form.
4. Increase the heat under the saucepan and boil the syrup until a thermometer registers 248 to 250 degrees. Immediately transfer the syrup to the glass measure to stop the cooking.
5. If using a hand-held mixer, beat the syrup into the whites in a steady stream. Don't allow the syrup to foll on the beaters or they will spin it onto the sides of the bowl. If using a stand mixer, pour a small amount of syrup over the whites with the mixer off. Immediately beat at high speed for 5 seconds. Stop the mixture and add a larger amount of the syrup. Beat on high for 5 seconds. Continue with the remaining syrup, using a rubber scraper to remove any syrup clinging to the glass measure. Lower the speed to medium and continue beating for up to 2 minutes, or until the mixture cools. If, after 2 minutes, the mixture is not completely cool, continue beating on low speed until cool.
6. Beat in the butter at medium speed 1 tablespoonful at a time. At first the mixture will seem thinner, but will thicken by the time all the butter is added. If at any time the mixture looks slightly curdled, increase the speed slightly and beat until smooth before continuing to add more butter.
7. Lower the speed slightly and drizzle in the liqueur and the raspberry puree.

To assemble:

1. Use a paring knife to cut a small hole in each cupcake, ensuring you don't cut all the way through to the bottom of the cupcake.
2. Spoon some of the lemon curd into each hole.
3. Fit a piping tip into a pastry bag. Fill halfway with the raspberry buttercream and pipe a swirl of icing onto each cupcake.