Chocolate Peppermint Roll

6 oz. semisweet chocolate
3/4 cup sugar
6 eggs, separated
1 teaspoon vanilla
1/4 cup cocoa powder
1.5 oz. red-and-white peppermint candy (about 9 - 1" round candies)
1 1/2 cups heavy cream

Heat oven to 400 degrees. Line an 11" x 15" jelly roll pan with aluminum foil and grease the foil generously. In a heavy saucepan, melt the chocolate over very low heat. Stir in 1/2 cup sugar. Off the heat, beat in the egg yolks with a wooden spoon. Stir in the vanilla. In a separate bowl, beat the egg whites to stiff peaks and stir about 1/4 of them into the chocolate mixture. Fold in the remaining egg whites. Gently spread the mixture in the foil-lined pan and bake for 8 minutes. Remove, cover with a damp cloth and let cool for 10 minutes. Turn out onto a strip of plastic wrap dusted with the cocoa powder. Fold the end of the plastic wrap over the end of the chocolate rectangle and, starting with that end, roll up jelly-roll style. Cover losely with the damp cloth and let cool completely, another 10-15 minutes. Crush the candy in the food processor. Beat the cream with 1/4 cup sugar to firm peaks and fold in the candy. Unroll the jelly roll and spread with whippped cream to within an inch of the edge and roll it up again. Cover and refrigerate. Before serving, slice in 1" slices with a serrated knife.