Peanut Butter Brownie Triffle

I took this to 2 big family parties over the weekend and everyone LOVED it! Thanks Mike/Jen for graduating to give me an excuse to make this big dessert that feeds a LOT of people!
1 fudge brownie mix
1 pkg (10 oz) peanut butter chips
2 pkgs (13 oz each) mini Reese's peanut butter cups
4 cups cold 2% milk
2 pkgs (5.1 0z each) instant vanilla pudding mix
1 cup creamy peanut butter
4 tsp vanila extract
3 cartons (8 oz each) frozen whipped topping, thawed
-Prepare brownie batter according to package directions, stir in peanut butter chips. Bake in a greased 13x9 baking pan for 20-25 minutes or until a toothpick inserted near center comes out with moist crumbs, (don't overbake) Cool completely on a wire rack, cut into 3/4 inch pieces.
-Cut peanut butter cups in half, set aside 1/3 cup for garnish. In a large bowl, whisk milk and pudding mixes for 2 minutes. Let stand for 2 minutes to soft-set. Add peanut butter and vanilla, mix well. Fold in 1 1/2 cartons whipped topping.
-Place a third of brownies in 5 qrt glass bowl, top with a third of Reese's peanut butter cups. Sppon a third of pudding mixture over the top. Repeat layers twice. Cover with remaining whipped topping and garnish with Reese's peanut butter cups. Refridgerate until chilled.