Chocolate Pudding Layer Cake

This is one of those crowd-pleasing treats that's hard to beat. With pudding and Cool Whip, kid's love it, but with cream cheese and a brownie-like crust, so do adults. It is one of our family's all-time favorites; the ultimate recommendation is that Hazel chose this over ice cream for dessert, something I've never seen happen with anything else I've made. I give you direct quotes:
Hazel (4) - "This is delicious-tastic!"
Ginger (3) - "This is scrumptious! Scrumptious means 'hungry' in Spanish, did you know that?"

What could be better than that?

Chocolate Pudding Layer Cake
3/4 cup cold butter
1 pkg (18.4 oz) chocolate cake mix
1 egg, lightly beaten
1 (8 oz.) pkg cream cheese, softened
1 cup powdered sugar
4 cups Cool Whip (a 12 oz. tub), divided
3 cups cold milk
2 small pkgs (3.9 oz.) instant chocolate pudding
2 T chocolate curls for each slice, optional

1. Preheat oven to 350. Cut butter into cake mix until crumbly. Add egg and mix well. Press into greased 9x13 pan. Bake for 15 to 18 minutes until set. Cool completely on wire rack.

2. In a small bowl, beat cream cheese and powdered sugar until smooth. Fold in 1 cup Cool Whip. Carefully spread over crust and refrigerate.

3. Whisk milk and pudding mixes for about 2 minutes. Let stand until soft set, a few minutes. Carefully spread over cream cheese layer. Top with remaining Cool Whip. Refrigerate 2 hours, garnish, cut and serve.

Recipe from some Taste of Home cookbook I looked at once