In a medium bowl whisk eggs and butter together. In a large mixer bowl add flour, sugar, and baking powder,stir well to combine all the dry ingredients together. Add the egg mixture to the flour mixture along with vanilla. Mix in medium speed to combine fully.Allow cookie dough to rest 10 minutes. Preheat the oven to 350°
Roll out dough in between parchment paper or plastic wrap or with flour, roll to 3/8" thick for thick cookies or 1/4" thick for thinner cookies.
Cut into the desired shape. Place cookies 2 inches apart, this will ensure the cookies bake evenly on the baking sheet. Do not overcrowd the baking sheets. Once you've cut the cookies, gather the cookie dough and re-roll until all the cookie dough is cut.
Place the cut cookie dough on parchment lined baking sheets.
Bake at 350° for 10-12 minutes. The bottoms of the cookies should be golden, the cookie should look pale in color not "browned"
Allow cookies to cool completely on the baking sheet.
Apply icing as desired. I place each color into piping bags, cut a small hole in the piping bags, and a larger hole for the white icing, and apply the icing to the cookies.
Allow the icing to dry completely for 24 hours before stacking cookies or wrapping them.