1. Beat sugar, mascarpone, raspberry liqueur and vanilla until smooth. Beat cream until stiff peaks form. Fold into mascarpone mixture.
2. Line the bottom of an 8 x 8-inch glass baking dish with half of the cookies, cutting some cookies in half to fit if necessary. Arrange half of the strawberries over the cookies. Spread half of the mascarpone over the strawberries. Dust with half of the cocoa powder. Repeat layering.
3. Cover and refrigerate for 4 to 6 hours.
4. To serve, dust with confectioners sugar. Garnish with a ring of sliced berries around the edge of the dish. Makes 12 servings.