2 cups graham cracker crumbs
1/2 cup baking cocoa, sifted
1 cup granulated sugar
1/2 cup (1 stick) unsalted butter, melted
Dark Chocolate Filling
16 ounces bittersweet chocolate, coarsely chopped
1 1/2 cups heavy cream
White Chocolate Filling
16 ounces white chocolate, coarsely chopped
3 cups heavy cream
2 teaspoons unflavored gelatin
2 tablespoons cold water
1 1/2 teaspoons vanilla extract
White and dark chocolate shavings or curls
Preheat oven to 350 degrees F.
Mix graham cracker crumbs, baking cocoa, sugar and melted butter in a bowl. Press evenly over the bottom and side of a 10-inch springform pan. Bake in the center oven rack
for 5 minutes. Cool on a wire rack.
Melt the bittersweet chocolate with the cream in a double boiler over hot but not simmering water, stirring to blend well. Pour into the prepared pan and chill for 30 minutes.
Melt the white chocolate with 1 cup of the cream in a double boiler over hot but not simmering water, stirring to blend well. Set aside.
Soften the gelatin in cold water in a small heat-proof bowl for 5 minutes. Place in a saucepan with water halfway up the side of the bowl. Heat for 3 to 4 minutes or just until the gelatin dissolves, stirring constantly, do not simmer.
In a large chilled bowl of an electric mixer, beat the remaining 2 cups cream with vanilla extract until soft peaks form. Beat in the white chocolate mixture and the gelatin mixture gradually. Spread evenly over the chilled dark chocolate layer.
Chill for 8 hours or overnight.
Run a thin knife around the side of the pan to loosen the torta. Place on a serving plate and remove the side of the pan. Garnish with grated chocolate or chocolate curls.