Place sheet of waxed paper on cookie sheet. In medium microwavable bowl, microwave 2 cups chocolate chips and 2 tablespoons vegetable oil uncovered on High 30 to 60 seconds, stirring every 15 seconds or until melted and smooth. Dip each brownie stack into melted chocolate. Using spatula or knife, evenly spread chocolate on brownies pops, scraping off excess chocolate. Immediately sprinkle with toppings.