1 box (about 19 ounces) brownie mix
¼ cup water
½ cup vegetable oil
2 packages (¾ ounce each) instant chocolate pudding
2 cups milk
4 cups vanilla ice cream, set at room temperature to soften
2 containers (8 ounces each) nondairy whipped topping
1 bar (8 ounces) chocolate, shaved (optional)
Prepare brownie batter with water, oil and egg according to package directions (your favorite brand may need a different combo of water, oil and egg) and bake in a 9-by-13-inch pan. Allow to cool.
In a large bowl, with an electric mixer, blend the pudding, milk and vanilla ice cream to create an airy, mousse-like mixture.
Crumble half the pan of brownies into a large trifle dish or glass bowl. Layer half of the chocolate mousse mixture over the brownies. Finish the first layer with one container of whipped topping. Repeat each layer with the remaining brownies, chocolate mousse and whipped topping. Garnish with chocolate shavings.