HEAT oven to 350°F. Prepare brownie batter according to package directions, using oil, water and 3 eggs, reserving packet of candy coated chips for later use. Spoon 3 tablespoons batter into each cone. (Do not overfill or cones will overflow during baking.) Stand cones upright in muffin cups.
BAKE 22 to 25 minutes or until toothpick inserted in center comes out clean. Cool completely on wire rack.
PIPE a decorative swirl of frosting on top of each brownie cone. Sprinkle with reserved candy coated chips.