A box of brownies (whatever brand you like, I particularly like fudge brownies), a package of small-size snickers
Follow instructions for making the brownies and once the batter is poured, dice four whole candy bars (or however many you'd like) and sprinkle over batter. Cook for the required length, and once cooled, eat! They taste gourmet for a great price. You can make these with any candy you like, and I'm sure they are just as good.