Sugar Cookies with frosting

When I first got married I worked as a teller in a local bank. One day a co-worker brought in some sugar cookies to share with all of us. After tasting the cookies we were all begging her for the recipe. Since then, when I want frosted sugar cookies, this is the recipe I use. It is now the recipe my mom always uses also. If you have ever purchased a Granny B's sugar cookie from the store or a vending machine (the big circle cookies usually with pink frosting), this is what these cookies are like. I think these cookies really need to be frosted, because the dough is not extremely sweet they need the sweetness from the frosting. However, my oldest son is not a frosting fan and is perfectly content to eat these cookies plain. Sour cream is the secret ingredient to these cookies.
****Since posting the cookie recipe, I've had several request for my frosting recipe also. So I have added it below. It comes from one of my first cookbooks, The Better Homes and Gardens New Junior Cook Book.

Sugar Cookies

Cream: 1 cup butter

work in: 1 cup sugar

Add: 2 eggs
1/2 teaspoon vanilla

Sift together 3 times (I just whisk it in a bowl):
3 cups of flour
1/2 teaspoon baking soda
1/2 teaspoon salt
1 teaspoon baking powder

add alternately with the dry mixture in thirds to the butter/sugar mixture:
1/2 cup sour cream

Chill: 2 to 3 hours

roll out and cut into shapes
bake at 375 degrees for 6 to 8 minutes

frost with favorite frosting

Butter Frosting

4 Tablespoons butter
2 1/3 cup powdered sugar
milk
3/4 teaspoon vanilla
for chocolate frosting add 3 Tablespoons cocoa

Put butter in bowl and beat with electric mixer until fluffy. Then add about half the powdered sugar. Then beat in 1 Tablespoon milk and the vanilla. Slowly add in the rest of the powdered sugar. Add more milk if needed. Add food coloring if desired. The makes enough frosting to ice half of a cake mix, so I usually double the recipe.