STEP ONEHEAT oven to 350° F. Line two 12-cup muffin pans with baking cups. Blend cake mix, water, oil and eggs in large bowl until moistened. Beat with mixer on medium speed 2 minutes or whisk by hand for 2 minutes. Fill paper baking cups 2/3 full with batter. Bake 18 to 22 minutes or until toothpick inserted in center comes out clean. Cool completely.
STEP TWOPOINT five-star tip of Easy Frost straight down above cupcake. Press nozzle gently (amount of pressure determines size of star). Release and lift nozzle, forming a star. Repeat placing stars very close together to cover surface of cupcake.
STEP THREEDECORATE cupcakes with berries by cutting strawberries into quarters vertically. Arrange berries on cupcake alternating 3 strawberry quarters (pointed side sticking straight up) with 3 raspberries (hull side down), then filling center with 3 blueberries. Garnish with small spring of mint. Serve immediately or refrigerate, covered, until ready to serve.