3 ounces unsweetened chocolate, chopped
1 cup unbleached all-purpose flour
½ teaspoon baking powder
½ teaspoon baking soda
¼ teaspoon salt
½ cup (1 stick) unsalted butter, at room temperature
1¼ cups sugar
2 large eggs
1 teaspoon vanilla extract
½ cup sour cream
½ cup water
1¾ cups sugar
¼ cup water
3 large egg whites
¼ teaspoon cream of tartar
1 teaspoon vanilla extract
½ teaspoon almond extract
2 cups (12 ounces) semisweet chocolate chips
3 tablespoons canola or vegetable oil
For the cupcakes: Fill the bottom of a double boiler with a few inches of water and put the chocolate in the top of the boiler. Over medium heat, stir the chocolate until it is smooth and melted. Remove from the water and set aside to cool slightly.
Sift the flour, baking powder, baking soda and salt into a medium bowl and set aside.
In a large bowl, using an electric mixer on medium speed, beat the butter and sugar until smoothly blended and creamy, about 2 minutes. On low speed, mix in the melted chocolate. On medium speed, add the eggs one at a time, mixing until each is blended. Add the vanilla and beat until the mixture looks creamy and the color has lightened slightly, about 1 minute. Mix in the sour cream until no white streaks remain. On low speed, add half of the flour mixture, mixing just to incorporate it. Mix in the water. Add the remaining flour mixture and mix until the batter looks smooth.
Heat the oven to 350 degrees. Line 12 muffin tin cups with paper liners.
Fill each liner with about cup batter. Bake just until the tops feel firm, about 20 minutes. Let the cupcakes cool for at least 10 minutes.
For the filling: Put the sugar, water, egg whites and cream of tartar in the top pan of a double boiler and beat on high speed until opaque, white and foamy, about 1 minute. Put that pan over the bottom of the boiler, which should contain a few inches of water. Be sure to keep the cord of the mixer away from the stove top. Beat on high speed over medium heat until the frosting forms a stiff peak that stands straight up if you stop the beaters and lift them out of the filling, about 12 minutes. Remove the top pan from the heat add the vanilla and almond extracts, and continue beating for 2 minutes to further thicken the filling. The filling will become firmer as it cools on the cupcakes.
Spoon the filling into a pastry bag fitted with a plain pastry tip or a large plastic freezer bag with a ½-inch-long hole cut in one corner. Pipe a spiral of filling into a 2-inch-high cone on top of each cupcake, leaving a thin outside border of the cupcake untouched. Place the topped cupcakes on a platter and refrigerate, uncovered, while you prepare the chocolate coating.
For the coating: Put the chocolate and oil in the top pan of the double boiler and place it over the bottom of the boiler, which should contain a few inches of water. Stir until the chocolate is melted and smooth. Transfer the chocolate coating to a small bowl and allow it to cool slightly, about 15 minutes.
Spoon the cooled chocolate over each chilled cupcake, making sure that none of the white cream shows. Let the cupcakes sit at room temperature for about 15 minutes to firm the coating slightly.
Peel off the paper liners and discard them. (This will make for a smooth chocolate-coated edge if any coating has dripped onto the liner.) Return the cupcakes to the platter and refrigerate for about 30 minutes to set the coating, then cover and refrigerate for at least 2 hours. Serve cold.