Sugar Cookie Bars

Name: Sugar Cookie Bars
Ingredients: For the sugar cookie bars; 3/4 cup butter, at room temperature; 1 cup sugar; 1/4 cup light brown sugar; 2 eggs; 1 teaspoon vanilla bean paste (or vanilla extract); 2 cups flour; 1 teaspoon baking powder; 1/2 teaspoon baking soda; 1/2 teaspoon salt; For the vanilla cream cheese frosting; 1/2 cup butter, at room temperature; 4 ounces cream cheese, at room temperature; 2 cups powdered sugar; 1 tablespoon heavy cream; 1 teaspoon vanilla extract; 1/4 teaspoon salt; sprinkles, for decorating