On these still-warm days, turning on the oven for a family dessert still seems like a bad idea. This super simple mousse dessert, however, seems like a great idea. Just add butter to the crust mix, milk to the filling mix and drizzle on the chocolate topping and you have a dessert that looks like you spent a lot more time making it than you did (you should chill it for about an hour). Oh, and it’s delicious.