Sugar Cookie Bars

Long time, no post. I've been making these for a long time and they're probably my favorite treat of late. They really turn out perfect every time and are so, so easy. Recipe from Mel's Kitchen Cafe. Of course.

Bars:
3/4 cup butter (1 1/2 sticks), softened to cool room temperature

3/4 cup granulated sugar
1/4 cup powdered sugar
2 large eggs
1 teaspoon vanilla extract
1/2 tablespoon lemon zest (optional, but don't leave it out cause it's so good in these)
2 1/4 cups all-purpose flour
1 teaspoon baking powder
1/2 teaspoon salt

Frosting:
6 tablespoons butter, softened
2 1/2 cups powdered sugar
3 tablespoons milk or cream
1/4 teaspoon vanilla extract
Sprinkles (optional)

Preheat oven to 375 degrees F. In a large bowl, cream together the butter, granulated sugar and powdered sugar until light and fluffy. Add the eggs and vanilla and mix for 1-2 minutes. Stir in the lemon zest, flour, baking powder and salt. Mix until combined. Lightly grease a 9X13-inch baking pan with cooking spray. Press and/or spread the sugar cookie mixture gently into an even layer into the bottom of the pan. Bake for 10-13 minutes. Don't overbake! The bars shouldn't have any color around the edges and barely be set in the middle. Let the bars cool completely before frosting. For the frosting, cream together the butter and powdered sugar until smooth (if the mixture has trouble coming together, add a drop or two of milk). Add in the vanilla and mix. Add the milk or cream and mix until the frosting is light and fluffy. Add food coloring, if desired.