4 squares Semi-Sweet Baking Chocolate
1/2 cup (1 stick) butter
3/4 cup sugar
1 tsp. vanilla
1/2 cup flour
2 cups cold milk
2 pkg. (4-serving size each) JELL-O Chocolate Flavor Instant Pudding & Pie Filling
1 tub (8 oz.) COOL WHIP Chocolate Whipped Topping, thawed, divided
Preheat oven to 350°F. Microwave chocolate and butter in large microwaveable bowl on HIGH 2 min. or until butter is melted. Stir until chocolate is completely melted. Add sugar; stir until well blended. Add eggs and vanilla; mix well. Stir in flour until well blended. Spread into greased 9-inch pie plate.
Bake 30 min. or until toothpick inserted in center comes out clean. Cool completely on wire rack. Scoop out center of brownie with spoon, leaving 1/2-inch-thick rim around edge and thin layer of brownie on bottom. (Reserve removed brownie pieces for later use.)
Pour milk into large bowl. Add dry pudding mixes. Beat with wire whisk 2 min. or until well blended. (Mixture will be thick.) Gently stir in half of the whipped topping and all but 1/2 cup of the reserved brownie pieces. Spoon into brownie crust; top with remaining whipped topping and remaining 1/2 cup brownie pieces. Refrigerate 2 hours or until set. Store leftover dessert in refrigerator.