Line a baking sheet with parchment paper
In a stand mixer fitted with the paddle attachment, cream the butter, sugar, nutmeg and extracts together until well combined and smooth.
Add the egg, mixing on medium speed to combine, scraping the bowl after.
Add flour, almond flour, and salt all at once and mix on low speed to combine.
Use a #100 portion scoop (2 tsp) to shape the dough. Roll the dough between your hands to create a smooth surface. Dip the cookies in the crystal sugar. Set the dough balls on the lined baking sheet about an inch apart. Use a ¼ tsp measuring spoon or your finger, to make an indentation in the top of the cookie. Pro Tip: If the dough is sticky, dip the spoon in more sugar before making the well in the center of the cookie. Chill the dough for about an hour or overnight. Pro Tip: This step can be done well in advance and the dough balls frozen in a zip lock bag until you are ready to bake. Preheat oven to 350°F
Line two doubled-up baking sheets with parchment paper. Space the chilled dough balls about 2 1/2 inches apart. Pro Tip: If you don't have enough pans for this, be sure the pans are cool before adding the next batch of cookies.
Bake for 10 to 12 minutes or until the cookies are golden on the bottom.
Place on rack and cool completely before filling.
Once the cookies are cool, Using a piping bag fitted with a star tip, pipe the buttercream on top of the cookies and decorate with luster dust and dragees or a dusting of nutmeg.