Thanks to Lifehacker for this:
Like most baking, crafting the perfect pot brownie is practically a science. You gotta de-carboxylate the bud, infuse the butter and (ideally) calculate the dosage.
But once they’re baked and divided into responsibly-portioned squares, there remains one final, expert move: a quick press with the waffle maker.
Waffling brownies—whether they contain THC or not—enhances them in two wonderful ways: It heats them, melting any chocolate chips and restoring them to their former gooey glory; and it crisps up their outsides into those delightful little waffled divots.
Plus, it makes the treat seem bigger through smooshing! Tiny, one-inch dosed squares get smashed into wider, warmer discs that urge you to slow down and enjoy your edible rather than pop the whole thing into your mouth in one go.
Brownies are, however, a temperamental waffled delicacy. A mere 10-second pressing in the iron is all you need to render them warm and gooey; any more than that and they lose all structural integrity.
Set your waffle maker to medium-high and place your brownie square in one of the quadrants (not in the center—those heavier grooves will slice your delicate brownie into pieces).
Close the waffle maker for 10 seconds, open it, then carefully lift the treat out of the grooves with chopsticks or the tines of a fork and slide it onto a spatula. Let cool for as long as you can stand it, then chow down.
Waffled brownies are obviously delicious on their own, but they are the perfect base for a blazin’ brownie sundae, so you should probably take advantage of that.