Cream together the butter and powdered sugar for 3-5 minutes with a mixer fitted with a paddle attachment.
Add in egg and vanilla until just combined.
Combine all dry ingredients and slowly add in while the mixer is on low.
Once dough comes together, chill until firm. Roll to ¼ inch thick and chill the dough again. Cut out cookies and place on parchment lined baking sheet. Press into sprinkles or sugar if desired. Bake for 8-10 minutes.