Prepare a piping pastry bag fitted with a large round tip and line two baking sheets with parchment paper or a silicone mat.

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

Preheat oven to 300ºF, or if using a convection oven, lower to 270ºF.

In a bowl over simmering water, whisk together granulated sugar and egg white powder until melted.

Add egg whites and whisk until completely melted, testing for sugar granules.

Transfer the melted syrup to a stand mixer and whip on low for 30 seconds, then medium for 2 minutes.

Increase to medium-high until stiff peaks form, about 13 to 15 minutes.

Fold in sifted powdered sugar and almond flour, and add food coloring.

Fold gently until the batter is shiny and flows in a ribbon.

Transfer the batter to piping bag, pipe onto prepared baking sheets, and let rest until dry.

Bake each tray for 15 to 20 minutes, then cool before filling.

Mix powdered sugar and meringue powder, adding water gradually until glossy and fluffy.

Divide icing into two bowls and color one black and one yellow; keep covered.

Pipe black icing for Santa's belt on half the shells, followed by yellow icing for the buckle.

Heat treat the flour by baking it at 350ºF for 5 minutes, then let cool.

Beat butter and sugars until creamy, add flour and extracts, mixing well.

Adjust consistency with milk or heavy cream if needed.

Pipe buttercream on a bottom shell and top with a decorated shell, rolling in shredded coconut.