Cream butter and sugar until fluffy. (I beat the butter and sugar together, for about 5 minutes, until it was really light and fluffy.)  Add the eggs, one at a time, mixing after each egg. Add vanilla extract and mix well. In a separate bowl, combine flour, salt, baking soda and stir with a wire whisk to mix well. Add to wet mixture and mix just until combined. Spread dough onto a greased(I used parchment paper lined) 13 x 18 baking sheet. (I like parchment, ’cause there is, absolutely, no sticking. JMO.  ) Bake at 375 degrees for 10-15 minutes, until light golden brown or until a toothpick comes out clean. The bars won’t look done so do the toothpick test. Cool completely and then frost.

Combine butter and cream cheese until smooth and creamy. Add vanilla extract and salt. Add powdered sugar in 1 cup increments until combined, then add milk and mix until smooth and spreading consistency. Spread over cooled sugar cookie bars.