preheat oven to 375 degrees an grease a 9 x 13 inch baking dish.
2In a medium bowl, combine flour, baking powder and salt. set aside. In a large bowl, cream together butter, and sugar until light and fluffy, about 3 minutes (the longer you beat it, the fluffier your cookies will be)
3Add egg and combine well.
add sour cream and vanilla and mix until completely blended. Slowly add the flour mixture an stir until well combined.
4Gently press the batter into the greased baking dish an spread out with hands. (if you butter your hands this will help with the stickiness.
Bake 17-20 minutes, or until edges become lightly golden. set aside to cool completely.
in a medium bowl, cream together butter and powdered sugar,and half half until light and fluffy. Stir in vanilla and salt, combine well. Add food coloring until desired color frost your cooled cookie bars evenly. cut into squares and serve.