A tray of Lucky Charms Frosted Cookie Bars on a white serving board, all cut up into equal squares. Marshmallows scattered beside the board.

Rainbow Lucky Charms™ Frosted Cookie Bars

  • Prep time:  20 Minutes
  • Total time: 1 Hour 45 Minutes
  • Servings: 24
  • Calories per serving: 200

Almost too pretty to eat! This sugar cookie bar with Lucky Charms™ cereal and candy sprinkles is just as cute as it is magical.

Ingredient List


  • 1 pouch (17.5 oz) Betty Crocker™ sugar cookie mix
  • 1/2 cup butter, softened
  • 1 egg


  • 1 container (16 oz) Betty Crocker™ Rich & Creamy vanilla frosting
  • Red, yellow, blue food colors


  • 1/2 cup Lucky Charms™ cereal
  • 1 tablespoon rainbow candy sprinkles
Unsliced Rainbow Frosted Cookie Bars topped with Lucky Charms™ cereal on a cutting board.


  1. Heat oven to 350°F. Line 13x9-inch pan with foil, leaving foil overhanging at 2 opposite sides of pan; spray with cooking spray.
  2. In large bowl, mix cookie mix, softened butter and egg with spoon until soft dough forms. Press dough in bottom of pan. Bake 18 to 23 minutes or until golden brown. Cool completely on cooling rack, about 1 hour. Remove bars from pan by lifting foil; peel foil away.
  3. Divide frosting into 3 small bowls; tint frosting with food colors to desired pink, yellow, blue colors. Drop colors of frosting by mounded spoonfuls onto cookie bar in a random pattern. With offset metal spatula, spread frosting by carefully swirling the different colors together. Top with cereal and sprinkles. To serve, cut bars into 6 rows by 4 rows.


  • We like using red, yellow and blue food colors for the frosting colors, tinted to match the colors in the Lucky Charms™ cereal marshmallows. Try different colors to switch up the look!
  • Using a flat, offset metal spatula makes swirling the frosting a breeze. If you don’t have one, use a butter knife or bagel spreader.

Rainbow Lucky Charms™ Frosted Cookie Bars Recipe Video