1. Preheat oven to 350°
2. In a stand mixer or with a hand mixer cream together room temperature butter & sugar until fluffy.
3. Add the eggs, and vanilla to the butter & sugar.
4. Sift together the all-purpose flour, baking powder & salt.
5. Mix together the flour mixture with the butter mixture. Do not overwork.
6. When the sugar cookie dough has come together cover with plastic wrap and chil for 20 minutes.
7. When the sugar cookie dough is firm but not too firm, on a lightly floured surface, use a rolling pin to roll out the dough to 1/8 thickness, and cut with your favorite cookie cutters.
8. Gently transfer the cookies to a prepared baking sheet that has been lined with a sheet of parchment paper. 
9. If you are making with sprinkles, decorate with sprinkles before baking.
10. Place cookies about 1 inch apart and bake for 9 minutes. Do not overbake but bake until they are lightly brown. (our family likes them a little undercooked)
11. Place the baked cookies on a Cooling Rack and cool completely.
12. If using frosting, cool completely before frosting.

For Frosting:

1. Placed softened 6 tablespoons of butter in a mixer with 2 cups of confectioners sugar and beat until fluffy. Add milk a little at a time as needed to get the correct consistency.