Heat oven to 325°F. Generously grease 12-cup Bundt pan with cooking spray.
Make cake mix as directed on box, using water, oil and egg whites. Divide batter among 3 small bowls. Add two drops yellow food color to 1 bowl; mix well. Add 1 drop red food color to second bowl to make pink. Add 2 drops red and 2 drops blue food color to third bowl to make purple. Pour half of the yellow batter into cake pan. Carefully pour half of the pink batter over yellow batter. Carefully pour half of the purple batter over pink batter. Repeat layers (do not mix colors).
Bake as directed on box until toothpick inserted near center comes out clean. Cool 10 minutes; remove from pan to cooling rack. Cool completely, about 1 hour. Place cake on serving plate.
In a large bowl, cream butter until light and fluffy. Beat in the confectioners' sugar, vanilla and enough milk to achieve desired consistency. Keep it to the stiff side, because we will heat it in the microwave to soften. Divide frosting among 3 small microwavable bowls. Microwave 1 bowl on High about 5 to 10 seconds; add two drops yellow food color and stir until frosting is smooth enough to drizzle. With spoon, drizzle yellow frosting back and forth over cake in striping pattern until all frosting is used. Microwave second bowl of frosting; add 2 drops red and blue food color to make purple. Drizzle frosting over cake in same striping pattern. Repeat with last bowl, adding 1 drop red food color to make pink frosting.
Place coconut in resealable food-storage plastic bag; add few drops green food color. Seal bag and toss until coconut is evenly tinted. Sprinkle coconut on serving plate around cake and in center for “Easter grass.” Could be decorated with some jelly beans on the “grass”.
The Evolution of Holiday Spectacles
Bakers routinely ruin dyed pastries by over-mixing colors into a muddy gray before the batter even hits the pan. Multi-colored baked goods gained traction during the mid-twentieth century when commercial food dyes became chemically stable enough to withstand high oven temperatures without fading. Historical baking traditions favored natural pigments derived from saffron, spinach, or beet juices, which produced muted earth tones rather than saturated neons. Culinary evolution shifted dramatically when boxed convenience mixes arrived on grocery store shelves, allowing home bakers to replicate elaborate bakery aesthetics with minimal prep work. Careful portioning of the batter into separate bowls prevents unwanted bleeding between the yellow, pink, and purple layers during the 325-degree bake time.
Mastering Drizzle Consistency
Frosting viscosity dictates whether the decorative stripes hold their shape or run together into an indistinguishable slick across the surface. Professional decorators maintain stiff peaks when mixing confectioners' sugar, butter, and milk because subsequent microwaving rapidly thins the fat molecules. Short five-to-ten-second intervals in the microwave transform the mixture into a pourable consistency that responds cleanly to spoon-drizzling techniques. Butter-based frostings behave differently than oil-based glazes, requiring precise temperature control to prevent separation during reheating. Substituting margarine for dairy butter alters the melting point significantly, which causes the decorative stripes to slide off the sides of the pastry rather than setting properly.
Tinting Coconut for Structural Contrast
Desiccated coconut often resists moisture, making the task of coloring shredded flakes an exercise in uneven blotching. Sealing the flakes inside a plastic storage bag with liquid dye allows mechanical shaking to distribute the pigment evenly across every microscopic fiber without saturating the meat. Achieving a convincing grass texture depends entirely on thorough distribution, since white patches destroy the illusion of spring foliage. Storing the finished dessert at room temperature under a cake dome preserves the moisture of the coconut while keeping the buttercream from forming a hard crust over the multi-colored interior.