BEST ever sugar cookies.....from Aliese's blog.

1 c. butter (just slightly cooler than room temp.--DON'T melt it!)
2 c. sugar
3 eggs
1 tsp. vanilla (I use some fabulous *smuggled* Mexican vanilla--if you use a cheaper extract, add a bit more)
1 c. sour cream
Cream these ingredients together until smooth. Then SIFT and add the following dry ingredients spool-fulls at a time so everything gets mixed properly.
1 tsp. baking powder
1 tsp. baking soda
6 c. flour
**After I had added about 1/2 of my dry ingredients, I needed to put my dough hooks into the mixer; the beaters weren't doin' the job quite as well. Chill the dough for as long as you can stand it (we made it about 3 hours), then roll and cut dough (rough 1/2" in thickness). Bake @ 400 for 8 minutes. Let 'em cool before you frost them. I just used a store-bought frosting and it was great.