Warm Chocolate Tortes with Raspberry Sauce

FOR SAUCE: In a food processor fitted with the metal blade, purée the raspberries. Pass the purée through a fine-mesh sieve into a clean container. Stir in the confectioners'sugar. Preheat an oven to 425 degrees F.

FOR TORTES: Butter four standard-sized (1/2 cup/4-fl oz) muffin tin cups, then sprinkle the bottom and sides with 2 teaspoons of the granulated sugar. Combine the bittersweet chocolate and butter in a heatproof bowl and set in a pan over (not touching) simmering water. Heat over medium heat, stirring continuously, just until the chocolate melts. Remove from the heat and let cool slightly.

Meanwhile, in a bowl, using an electric mixer set on high speed, beat together the egg yolks and the 1/4 cup granulated sugar until thick, about 4 minutes. Reduce the mixer speed to medium and slowly pour in the melted chocolate. Beat in the orange zest.

In a clean bowl, using clean beaters, beat the egg whites until very soft peaks form. Sprinkle in the remaining 1 teaspoon granulated sugar and continue to beat until semisoft peaks form. Using a rubber spatula or whisk, fold the flour into the chocolate batter alternately with the egg whites, beginning and ending with the flour.

Pour the batter into the prepared molds, filling to within 1/8 inch of the rims. Place 2 pieces of white chocolate on top of each mold; they will sink a little during baking. Place the pan in the center of the oven and immediately reduce the heat to 375 F. Bake until puffy and a thin but firm crust forms on top, about 8 minutes. Do not open the oven door during the first 6 minutes of baking. Transfer the pan to a rack and let rest about 5 minutes to ease unmolding.

Meanwhile, run a vegetable peeler along the block of white chocolate to form curls for garnishing the tortes. Keep the curls cool until serving.

Run a sharp paring knife around the edge of each cup and quickly invert the tortes onto the rack. Transfer the tortes to individual plates, top sides down. Pour the raspberry sauce evenly over the tortes and then sprinkle with the chocolate curls. Scatter fresh raspberries around each torte. Serve immediately.