Preheat the oven to 350 degrees. In a small bowl, whisk the flour, cinnamon, nutmeg, salt and baking powder together. Set aside.
In a large bowl, with an electric mixer on low speed, mix the butter, sugar and brown sugar together. Add the vanilla. Gradually blend the flour mixture into the butter mixture a little at a time.
Form the dough into a ball. Cover with plastic and let the dough rest in the refrigerator for 30 minutes.
Lightly flour a clean, dry work surface. (I like to use a big bread board.) Add the ball of dough and roll it out until it is approximately 1/4 inch thick.
Cut the dough into round shapes and place the shapes on an ungreased cookie sheet. (If you would prefer to use other cookie cutter shapes, that is fine.) Reroll scraps of dough and continue cutting until all dough is used.
Bake for 10 to 15 minutes, or until lightly browned on the bottom. Cool for at least 10 minutes before eating. Makes about 3 dozen cookies.