Preheat oven to 350°F. Spray 11×17-inch rimmed baking sheet with cooking spray and line the bottom with parchment paper.

Beat cake mix, 1 cup water, eggs and oil in large bowl with an electric mixer on low speed until blended, about 30 seconds. Beat on medium speed 2 minutes.

Divide batter evenly into 3 small bowls, about 1-1/4 cups each. Stir a few drops of pink food coloring into one bowl, purple into another and green in the last.

Pour pink batter onto one third of the baking sheet and spread evenly. Pour purple batter in the middle third of the baking sheet and spread evenly and pour green onto last third and spread evenly.

Bake 15 to 18 minutes, until toothpick inserted in center comes out clean. Cool completely on a wire rack.

Invert onto work surface and remove parchment paper. Use the rim of a half-pint jar to cut into 24 circles or break each color into small pieces.

Beat heavy cream in a large bowl with an electric mixer on low speed until thickened, about 2 minutes. Slowly beat in confectioners’ sugar until blended. Beat in cream cheese and vanilla until blended. Beat on medium speed until thick and fluffy, about 2 minutes.

Divide and layer cake and filling evenly into twelve 1/2-pint jars. Crumble cake scraps and sprinkle onto jars. Top each with a PEEPS® Party Cake Marshmallow Chick.