Step 1

Preheat oven to 350 degrees. Coat the cake pans with flour based baking spray.

Step 2

Sift together flour, baking powder, and salt; set aside. Whisk together egg whites and milk in a separate bowl; set aside.

Step 3

Beat the butter using the paddle attachment until soft and creamy. Add sugar gradually and beat until light and fluffy. Scrape down the bowl as needed. Beat in tropical punch flavoring oil.

Step 4

Add flour mixture alternately with the egg white/milk mixture. Begin and end with flour mixture and beat until smooth on medium-low speed after each addition.

Step 5

Divide batter between five bowls, about 1 2/3 level cups per bowl. Tint each bowl with the food color so that you have a bowl of bright pink, orange, yellow, green, and purple. Add food color a little at a time until a brilliant color is achieved. Pour the batters into the prepared pans.

Step 6

Bake the cakes at 350 for 25-30 minutes. Let cool slightly in pan, then turn out and cool completely on a wire rack. Level the tops of the cakes using a serrated knife or cake leveler.

Step 7

Combine the butter and sugar in the bowl of an electric mixer fitted with the whip attachment. Beat on low speed until just combined. Add a little milk or cream and increase mixer speed. Add milk or cream a tablespoon at a time until it comes to spreading consistency. Beat in orange extract. Whip on high speed until the buttercream is white and fluffy.

Step 8

Remove 1 1/4 cups of the buttercream to a piping bat fitted with a large closed star tip. Set aside for later use.

Step 9

Place the purple cake layer on a cake board and top it with 1/3 cup of the buttercream. Continue to stack the cake layers and frosting in this order, purple, green, yellow, orange, pink. Frost the entire cake evenly with the buttercream. Use a bench scraper or cake smoother to achieve an even coat. Refrigerate the cake until the buttercream is firm, about 1 hour.

Step 10

Place the corn syrup and water in a small kitchen-dedicated spray bottle; shake the bottle well to incorporate. Lightly mist the cake’s sides with the mixture and refrigerate 10 minutes.

Step 11

Pour the Nerds candy onto a large baking sheet. Remove the cake from the refrigerator and roll the cake’s sides in the candy. Place one hand on the bottom cake board and the other on the top of the frosted cake and quickly roll, picking up the cake this way to re-roll. Shake the pan to redistribute the candy across the pan and roll again. Allow the weight of the cake to naturally pick up the candy. The cake should be mostly covered with the candy when you turn it upright. If you see bare spots, pat Nerds candy onto the areas with your hands.

Step 12

Use the reserved bag of frosting to pipe tall swirls of buttercream on top of the entire cake; immediately sprinkle with more candy (about 2 tablespoons).

Step 13

Using an art brush, coat one of the half sphere cavities with the melted chocolate; freeze for 5 minutes. Re-coat the cavity with more chocolate to make it sturdy; freeze again until solid. Turn the half sphere out onto a work surface. Heat a metal cocktail pick on with a chef’s torch (or on the stove eye) for a few seconds, then use it to melt a hole in the top center of the chocolate dome. Lightly mist the dome with the corn syrup spray; let set 1 minute.

Step 14

Roll out the kneaded fondant to 1/4-inch thickness and drape over the dome. Smooth evenly to fit around the semicircle, then use a small knife to cut round the bottom edge. Use a toothpick to poke a hole in the top center of the dome where the chocolate was pierced.

Step 15

Place a little of each pink, orange, and yellow gel food colors in small condiment cups. Add drops of vodka to thin. Using a paint brush, paint 1/3 of the beanie with the pink gel food color (see images for design). Pat with the textured paper towel. Repeat the process using the orange and yellow food colors. Let stand until dry, about 25 minutes.

Step 16

Meanwhile, cut a small 3-inch propeller using scissors from a piece of green craft paper. Punch a hole in the center using a metal cocktail pick or an X-Acto knife.

Step 17

Press the bamboo skewer slightly off center in the top of the cake with the blunt side exposed. Gently balance the beanie on top of the skewer. Place a beaded toothpick in the top center hole of the beanie, so that the bead sits on top of the hat. Thread the propeller on top and give it a test spin. If the hole isn’t big enough for it to spin, widen it slightly.

Step 18

Store cake in the refrigerator for longevity. Bring it to room temperature before serving.