Preheat oven to 350 degrees and spray a 9 x 13" pan with nonstick spray.

Prepare cake batter as directed on box and pour into 9 x 13 pan.

In separate bowl, combine ricotta, sugar, eggs, and vanilla and mix well.

Carefully pour the cheese mixture over the top of the unbaked cake batter, spreading as evenly as possible.

Bake the cake at 350 degrees for 1 hour, or until a toothpick comes out clean. Cool completely. Do not frost until completely cool. Best to refrigerate overnight.

Make chocolate pudding according to package directions and fold in cool whip. Spread over the cake, cover and refrigerate at least 6 hours before serving.

Decorate with cherries and sprinkles, Christmas sprinkles or simply dust with cocoa powder.