1 (22 ounces) package brownie mix
1/3 cup Kahlua
3 envelopes chocolate mousse mix
5 large Heath bars
16 ounces whipped topping
Bake the brownies using the package directions for a 9x13-inch baking pan. Pour the Kahlua over the hot brownies. Let stand until cool. Cut into bars.
Prepare the mousse mix using the package directions. Crush the candy in a large sealable plastic food storage bag with a rolling pin.
Layer the brownies, mousse, whipped topping and candy 1/2 at a time in a large deep trifle dish. Chill, covered, for 8 to 12 hours.