In the bowl of a stand mixer, cream the butter, sugar, vanilla, and egg, until light and fluffy.
Scrape down the sides of the mixing bowl, and mix again.
In a separate bowl, mix the flour, baking powder, baking soda, and salt, until well blended.
Add the flour mixture to the mixing bowl a little at a time, mixing between additions until all of the flour mixture and butter mixture have been blended thoroughly.
Scrape down the sides of the mixing bowl, and mix again until well blended.
Remove the mixing bowl, and chill dough for 15 minutes in the refrigerator.
Turn oven on to 350 degrees.
Line 2 cookie sheets with parchment paper, and set aside.
Place colored nonpareils in a small dish.
Remove cookie dough from the refrigerator, and roll it into 2 inch balls, then roll balls in nonpareils, and place on the parchment paper.
Bake for 10 - 12 minutes for soft chewy cookies.
Remove the cookie sheets to a wire rack and cool for 10 minutes before removing cookies to finish cooling.
Serve and Enjoy!