8 sheets phyllo dough, thawed
1 cup oil
½ cup cocoa
1 container vanilla mousse powder
1 container chocolate mousse powder
64 ounces whip topping
Bittersweet chocolate coating for garnish
Combine ½ cup oil with ¼ cup cocoa. Place 1 phyllo sheet on your work surface. Cover remaining sheets with a damp paper towel. Using a pastry brush, brush 1/4 the cocoa mixture over phyllo covering the entire sheet. Sprinkle with sugar to coat evenly.
Continue stacking with 3 more sheets of phyllo. You should have a stack of 4 sheets. With a sharp knife, cut into rectangles measuring 3"x5". Place onto a sheet pan lined with a Silpat or parchment. Bake at 400 degrees for 12-15 minutes. Remove from oven and let cool on wire rack. Repeat with remaining phyllo.
Place 32 ounces whipped topping and mousse powder in the bowl of electric mixer. Whip together on medium speed until firm and increased in volume. Fit a pastry bag with a large star tip (#825) and fill with mousse. Repeat with other flavor.
To assemble Napoleon:
Put one phyllo rectangle onto work surface. Pipe vanilla mousse in a zig-zag fashion, covering the entire piece. Place another phyllo rectangle on top. Pipe chocolate mousse on top. Top with a third phyllo rectangle. Pipe a rosette of vanilla mousse in the center.
Melt bittersweet chocolate coating. Put melted chocolate into a parchment bag or squeeze bottle. Pipe a squiggle or pattern of your choice onto parchment paper. Let set and release form paper with a metal spatula. Place in center of rosette.