Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
1/2 cup unsalted butter, 3/4 cup granulated sugar, 1/4 cup light brown sugar
Beat in the egg and vanilla extract until well combined.
1 large egg, 1 teaspoon vanilla extract
Stir in the red food coloring and white vinegar.
1 tablespoon red food coloring, 1 teaspoon white vinegar
In a separate bowl, whisk together the flour, baking soda, and salt.
1 1/2 cups all-purpose flour, 1/2 teaspoon baking soda, 1/4 teaspoon salt
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix.
1 1/2 cups all-purpose flour, 1/2 teaspoon baking soda, 1/4 teaspoon salt, 1/2 cup unsalted butter, 3/4 cup granulated sugar, 1/4 cup light brown sugar, 1 large egg, 1 teaspoon vanilla extract, 1 tablespoon red food coloring, 1 teaspoon white vinegar
Spread the batter evenly into the prepared baking pan.
Bake for 20-25 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Let the bars cool completely in the pan before frosting.
While the bars cool, make the frosting. In a medium bowl, beat together the softened cream cheese and butter until smooth and creamy.
4 ounces cream cheese, 1/4 cup unsalted butter
Gradually add the powdered sugar and vanilla extract, beating until smooth.
2 cups powdered sugar, 1 teaspoon vanilla extract
Spread the frosting evenly over the cooled cookie bars. Cut into squares and serve.
