Bake cake as directed. Fill each muffin cup 2/3 full. In lg bowl, beat cream cheese and sugar until fluffy. Beat in egg. Stir in 1 cup chocolate chips.
Drop 1 heaping tsp of filling onto each muffin cup. Bake as directed on box. Cool cake. In sauepan over medium heat, bring heavy cream to a boil, stirring constantly. Place remaining choclate chips in a bowl. Pour cream over chocolate chips.. Stir until smooth.
Let coo about 10 mins, until slightly thickened. Spoon over cupcakeas. Let set before serving.