In a large bowl or stand mixer, combine sour cream, sugar, butter, eggs and vanilla. Mix well until incorporated.
In a medium sized mixing bowl, combine flour, baking powder, baking soda, and salt. Slowly add the dry ingredients to the wet ingredients.
You can either roll out the dough 1/4 inch thick on a lightly floured surface and cut cookies in circular shapes. Or you can scoop out the dough with a cookie scoop, roll the dough in a ball in your hand and lightly flatten into a circular shape. Place on an un greased cookie sheet and back for 10-12 minutes. They will be a light brown around the edges. Transfer to a cooling rack and cool completely before frosting.
To make the butter cream frosting:
Add the butter to a mixer and cream for about 2 minutes. Slowly add in powdered sugar and beat until smooth. Add vanilla and milk and continue to beat until smooth. Add food coloring if desired.