In a mixer, cream sugar and butter until fluffy.
Add each egg, one at a time, beating after each egg until well combined.
Add sour cream and vanilla and beat well.
Add your flour, baking soda, baking powder, and salt. Mix until combined. Your dough will be sticky.
Divide your dough into two pieces. Flour a cutting board and flatten dough into 1-1/2 inch thick rectangles. Wrap dough in plastic wrap and put in the fridge for at least 2 hours.
Remove, from fridge, one rectangle at a time. Put dough back on your floured surface and roll out to ¼ inch thick.
Using a 2"-3” cookie cutter, cut out cookies and place on a cookie sheet lined with parchment paper. Work in small batches, so dough stays cold
Bake at 375 for 8 minutes, until cookies are a tiny bit brown around the edges.
Allow the cookies to cool completely before frosting them. (Frosting recipe is below.)
Store in an airtight container at room temperature. Cookies can be stored in freezer, if they are not frosted.