Dark Chocolate & Raspberry Buttercream Cupcakes with Chocolate Glaze pt 2 (frosting)
5 large egg whites (30g each–total 150g)
1 cup plus 2 tablespoons superfine granulated sugar
3/4 pound (3 sticks) unsalted butter, softened, cut into cubes
2 teaspoons pure vanilla extract
Pinch of salt
*1/2 pint fresh, rinsed & dried raspberries (optional)
Wipe the bowl of an electric mixer with paper towel and vinegar, to remove any trace of grease. Add egg whites and sugar, and simmer over a pot of water (not boiling), whisking constantly, until temperature reaches 160 degrees F, or if you don’t have a candy thermometer, until the sugar has completely dissolved and the egg whites are hot.
With whisk attachment of mixer, begin to whip until the mixture is thick, glossy, and cool. Switch over to paddle attachment and, while mixing on medium speed continuously, add softened butter in chunks until incorporated, and mix until it has reached a silky smooth texture (if curdles, keep mixing and it will come back to smooth). Add vanilla and salt, mix well. Add in the raspberries.