Quick & Easy Chocolate Covered S’mores Pretzels

pretzels 30 chocolate candies, halved (I used snack-size Hershey’s bars) 15 full-sized marshmallows, cut in half 1 cup candy melts or chocolate chips 1/2 teaspoon vegetable oil For topping: Sprinkles, chopped nuts/cookies/graham crackers, etc., optional