Line a 9×13 inch pan with tin foil. Pre-heat oven to 350 degrees.
In a large bowl combine cake mix, hot chocolate mix, 1 stick of melted butter and 1 eggs. Mix with a wooden spoon until a thick dough (cookie dough texture) forms. I use my hands to get it mixed good. Press the dough into the bottom of the foil lined pan. That is your crust.
For the topping, in another large bowl combine the cream cheese and butter and beat with a mixer until smooth. Add eggs one at a time until incorporated. Add the powdered sugar 1/2 cup at a time until it’s all smooth. Finally add the Mallow-Bits and fold them in. Pour on top of the crust and spread it out evenly.
Bake in 350 degree pre-heated oven for 30-35 minutes. The center of the cake should still be giggly and not set completely. Let the bars cool completely before cutting into them.