Halloween Candy: Reese’s Peanut Butter Cups. 2 1/5 miniatures=100 calories. The full-size Reese’s Peanut Butter Cup has more than 100 calories, so you’ll likely feel more satisfied by two minis (we’re guessing you won’t bother carving out 1/5 of a miniature Reese’s cup). Plus, it will take you longer to unwrap them. More packaging always equals more time to think about if you really want another serving.