In a medium bowl, whisk together Peetz S.M.A.R.T (Sorghum, Millet, Arrowroot, brown Rice, Tapioca) Blend with the baking powder.
In the bowl of a stand mixer, fitted with a paddle attachment, beat together the butter and the sugar for 2 minutes.
Add the eggs and vanilla extract. Beat for 1 minute.
Sprinkle over the dry ingredients.
Beat just until combined.
Divide dough in half. Shape into a round and flatten into a disk.
Wrap each disk in plastic and refrigerate for one hour.
Line two baking sheets with parchment paper.
Remove dough from fridge and sprinkle some Peetz S.M.A.R.T (Sorghum, Millet, Arrowroot, brown Rice, Tapioca) Blend on the countertop.
Roll sugar cookie dough to 1/8 of an inch thick.
Cut out cookies and place on the baking trays, keeping space between.
Place the filled cookie trays in the refrigerator for 15 minutes.
Preheat oven to 350 F.
Once chilled, place cookies in the oven and bake for 10 to 12 minutes.
Remove from oven and let cool for 2 minutes before transferring to plate.
Let cool completely before decorating with Best Ever Royal Icing.