skewers; a small spray bottle; a pastry bag fitted with a large tip
For the cake: Preheat the oven to 350 degrees F. Spray a large metal mixing bowl (about 10 1/2 inches in diameter) with nonstick cooking spray and set aside.
Combine the cake mix, eggs, oil and 1/2 cup water in a large bowl. (The water and oil is less than what the box instructions call for.) Mix with an electric mixer on medium speed until fully combined, about 2 minutes. Pour the batter into the prepared bowl and bake until a skewer inserted in the center comes out clean, 45 to 50 minutes. Let cool for 15 to 20 minutes in the bowl, then remove from the bowl and let cool completely on a cooling rack, about 2 hours.
For the nest: Meanwhile, spray the same bowl you used to bake the cake in with nonstick cooking spray.
Melt the butter and marshmallows together in a large pot over low heat, stirring frequently. Add the white chocolate and cinnamon and stir until fully combined. Add the brown and yellow food coloring and mix until blended. Add the chow mein noodles and mix until all the noodles are coated with the marshmallow mixture. Transfer the mixture to the prepared bowl and quickly press into the bowl to form a nest shape. If your hands start to stick, spray them with cooking spray (Caution: the mixture is hot, but you have to work quickly or it will harden; you can wear gloves for this step if necessary). Let cool about 2 hours.
Remove the nest from the bowl and line the bowl with plastic wrap, letting some plastic wrap hang over the edge of the bowl. Place the nest back in the bowl, over the plastic wrap. Store in the refrigerator until ready to use.
For the eggs: Place the white chocolate in a small microwave-safe bowl. Heat in 30-second increments, stirring after each, until melted, 1 1/2 to 2 minutes. (Do not overheat.) Divide the melted chocolate into 2 bowls. Whisk 6 drops blue food coloring and 5 drops green food coloring into one bowl until a robin's egg blue color is created.
Gently push the pointed end of a skewer into the bottom of each chocolate egg, slightly off-center (do not hit the seam of the egg, or the egg will split along the seam). Gently dip the egg into the blue chocolate and turn until the egg is evenly coated. Lift the egg out of the blue chocolate and hold above the bowl to allow excess to drip off. Push the flat end of the skewer into a foam block or container of sugar or salt to allow the egg to dry undisturbed. Repeat this process to dip 4 more eggs into the blue chocolate. Dip the remaining 5 eggs in the white chocolate in the same manner. (If at any point the melted chocolate becomes too thick, microwave for 30 seconds more to loosen.) Set the eggs aside to harden for 1 hour.
Remove the eggs from the skewers and place on a paper towel-lined tray.
Combine 4 drops green food coloring and 4 drops blue coloring with 1 tablespoon water in a small spray bottle. Lightly spritz the green mixture onto the eggs in a speckled pattern. Allow the eggs to dry again for 1 hour.
For decorating: Spread 1 can of the cream cheese frosting into the nest, leaving the outer border unfrosted.
Slice 1 1/2 to 2 inches off of the flat side of the cake so that it will fit well inside the nest. Using a spoon, remove some cake to hollow out a depression in the top (the flat side) of the cake, leaving a 2-inch border intact along the outer edge of the cake.
Place the cake hollowed-side up into the frosted nest. Fill a pastry bag fitted with a large tip with the remaining cream cheese frosting and frost the top of the cake; spread evenly using an offset spatula or a spoon. Sprinkle the toasted coconut over the top of the cake, making sure to coat completely. If not using immediately, refrigerate. (Let the refrigerated cake come to room temperature for 1 hour before serving.)
Using the excess plastic wrap, pull the nest cake out of the bowl and place on a cake stand or platter. Arrange the eggs in the nest, then decorate with mint sprigs and edible flowers, and serve.