Editor’s note: I tried the recipe myself, and my husband, who normally wouldn’t touch tofu—or any foods that had even come in contact with tofu—found it delicious and had no idea a healthy swap had been made. 
Tofu is a good substitute for butter. A 7 oz piece of tofu contains about 6-7 g of fat. If you’d like to cut down on calories and fat further, use more cocoa powder and reduce the amount of dark chocolate you use. More cocoa powder will make your tofu brownie taste very light, not too sweet and will add that sophistication we often associate with artisanal bakeries….