Preheat oven to 350 degrees F.Lightly grease three 8-inchcake pans and line bottomswith parchment paperrounds. Whisk togetherflour, baking powder, maltpowder, and salt in a bowl. Whisk together oil,half-and-half, sugar, vanilla,coconut extract, and wholeegg in a separate bowl untilsmooth. Fold in flour mixturejust until incorporated. Beategg whites with an electricmixer on medium-high speeduntil stiff peaks form, 1 to2 minutes. Fold egg whitesinto batter just untilcombined. Divide batter amongprepared pans. Bake until atoothpick inserted in thecenter comes out clean, 18to 22 minutes. Cool in panson a wire rack for 15 minutes,then invert onto racks tocool completely. Place one layer on acake plate and frost top with1 cup Coconut Buttercream.Repeat two more times.Frost sides with remainingCoconut Buttercream.Stir together food coloringand 2 drops water in a bowl.Dip the tip of a wide, stiffpaintbrush into the mixture.Holding the brush 6 to 8inches from the cake, gentlyfling the mixture onto icedcake. Repeat for desiredeffect. Spread Phyllo Nestaround the base of the cake,and nestle robin's egg candies in nest.