Sugar Cookie Bars

Bars
1 cup butter, softened
2 cups sugar
4 eggs
2 tsp vanilla
5 cups flour
1 tsp salt
1/2 tsp baking soda
Frosting
1 cup butter, softened
1 tsp vanilla
4 cups powdered sugar (approximately)
1/3 cup milk (approximately)

Preheat oven to 375 degrees.  Line a 13 x 9 in pan with foil.  Spray with non-stick spray.
In an electric mixer cream butter and sugar until light and fluffy, about 2 minutes.  Add eggs, one at a time, mixing well after each egg.  Stir in vanilla. In another bowl mix together the flour, salt, and baking soda.  With the mixer on low, slowly add in the flour mixture, until just combined. Spread the dough into the prepared baking pan.  Bake for 10-15 minutes, a tester should come out clean. Allow to cool completely before frosting.
To make the frosting cream the butter until fluffy.  Add vanilla, milk, and 1/2 of the powdered sugar.  Continue adding powdered sugar to get to the right consistency.  You might have to adjust the milk or powdered sugar to make it spreadable.  Spread over the cooled bars.