The day before:
Cut the chocolates into small pieces. Place in the bowl of a double boiler over simmering water to melt. Add the butter to the chocolate and allow to melt. In a medium-sized bowl, stir together the sugar and cornstarch. Stir the melted chocolate into the sugar mixture. Add the eggs, egg yolks and Grand Marnier and mix until thoroughly combined. Place the mixture in a sealed container and refrigerate overnight.

The day of:
Preheat the oven to 375* F.
Line a cookie sheet or sheet pan with greased parchment paper and place an additional cookie sheet or sheet pan underneath to prevent the bottoms from over-cooking. Cut eight strips of parchment paper to 9 ½ inches by 3 inches. Grease and flour both sides of the strips. Place eight ring molds onto the prepared cookie sheet. Form the parchment strips into rings, placing them inside the ring molds. (If you do not have ring molds, you may use clean tuna cans with the tops and bottoms removed). Scoop the chilled cake batter into the ring molds so that each mold is filled 2/3 full.

Bake for15-20 minutes or until the cakes are cooked around the edges, but are still a bit jiggly in the center. Remove the cakes from the oven, allow them to sit for 2-3 minutes. While waiting, dust the cakes with confectioner sugar.

Transfer the cakes with a spatula and a pair of tongs into the middle of eight dessert plates, making sure not to puncture the center, or the chocolate pudding will ooze out. Gently remove the rings and paper and serve immediately. This cake can be topped with a small amount of whipped cream or vanilla bean ice cream, but it will be wonderful on its own.