Prep the Ingredients: Gather all ingredients and set aside. Prepare a large piping bag fitted with a ½-inch round tip. Line two baking sheets with parchment paper or silicone mats.

Sift and Combine: Sift together the powdered sugar and almond flour, then set aside.

Heat the Mixture: Place a bowl over a pan of barely simmering water. Add the sugar, egg white powder (if using), and both fresh and carton egg whites. Whisk until the sugar melts and the mixture is frothy. Avoid cooking the whites or overheating the sugar syrup.

Whip the Meringue: Transfer the mixture to a stand mixer. Whisk on low for 30 seconds, gradually increasing to medium until fluffy. Then whisk on medium-high until stiff peaks form. The peaks should be glossy and stand up straight.

Combine Ingredients: Gently fold the sifted powdered sugar and almond flour into the stiff meringue until incorporated.

Color the Batter: Divide the batter into three bowls for different colors or keep one color if preferred. Add food coloring and fold until you reach a glossy, thick, and flowing consistency.

Pipe the Shells: Transfer the batter to piping bags. Pipe 2.3-inch circles onto the baking sheets, holding the bag at a 90-degree angle.

Bang the Trays: Tap the trays on the counter to release air bubbles. Pop any remaining bubbles with a toothpick.

Dry the Shells: Let the shells dry for 20-40 minutes, or until they feel dry to the touch.

Bake: Preheat the oven to 300°F. Bake one tray at a time for 15-20 minutes, rotating the tray after 5 minutes. Macarons are done when they have a deeper color and solid feet. Let cool completely before filling.

Grind the Eggs: Process the Cadbury eggs in a food processor until finely ground.

Beat the Butter: Using an electric mixer, beat the butter for 1 minute. Add the powdered sugar and ground Cadbury eggs. Mix on low to combine, then increase speed to medium-high for 1 minute.

Adjust Consistency: Add milk and vanilla. Mix until smooth. Adjust thickness with more milk or powdered sugar as needed.

Pipe the Buttercream: Transfer to a piping bag fitted with a round tip.

Combine Ingredients: Sift powdered sugar and cocoa powder in a bowl. Set aside.

Beat the Butter: Beat the softened butter on medium-high speed for 1 minute.

Mix the Frosting: Add the powdered sugar, cocoa powder, and milk to the butter. Mix on low, then increase to medium-high for a smooth consistency. Add vanilla and mix.

Adjust Consistency: Add more milk or powdered sugar as needed. The frosting should be smooth and thick.

Pipe the Nest: Transfer to a piping bag fitted with a small grass tip.

Fill the Macarons: Pipe Cadbury Egg Buttercream onto the center of each macaron shell. Top with another shell.

Create the Nest: Pipe a tall ring of chocolate frosting on the top shell to form a nest. Sprinkle toasted coconut for texture if desired.

Add Eggs: Place mini Cadbury eggs in the nest.

Refrigerate: Store in the fridge for up to 5 days.

Freeze: Freeze for up to 1 month. Let thaw and come to room temperature before serving.