I have been making this one for years. I have seen many recipes using cake in the trifle, but I prefer the brownies, since they are my favorites. I always want more pudding than the original recipe called for, so I doubled the pudding here.
Heat oven to 350 degrees F. Grease bottom only of 13x9-inch pan with cooking spray. In medium bowl, stir brownie mix, water, oil and eggs until well blended. Spread in pan.
Bake 28-30 minutes or until toothpick inserted 2 inches from side of pan comes out almost clean. Cool completely, about 1 hour 30 minutes.
Cut brownies into 1-inch squares. In bottom of 3-quart glass bowl, place half of the brownie squares. Make pudding mix as directed on box for pudding, using milk. Pour half of the pudding over brownies in bowl. Top with half each of the toffee bits and whipped topping. Repeat with remaining brownies, pudding, toffee bits and whipped topping.
Cover; refrigerate at least 4 hours before serving. Store covered in refrigerator.