• Preheat the oven to 350ºF and grease a 9X13-inch baking pan. In a large bowl combine melted butter, sugar, and milk. Add eggs and mix thoroughly.
  1 cup (2 sticks) butter, 2 cups granulated sugar, 2 tablespoons milk, 2 large eggs
• Add flour, baking powder, cream of tartar, and salt to bowl. Stir until well combined. The batter will be very thick.
  2 ¾ cup all-purpose flour or gluten free flour, 1 teaspoon baking powder, ½ teaspoon cream of tartar, ¼ teaspoon salt
• Spoon batter into the prepared pan and press down evenly. Sprinkle all over with the combined sugar and cinnamon topping mixture.
  2 tablespoons granulated sugar, 1 ½ teaspoons cinnamon
• Bake for 30-33 minutes (about 5 minutes longer if using gluten-free flour) or toothpick inserted in middle comes out clean. Cool for about 20-30 minutes before drizzling topping on.

Cinnamon Vanilla Glaze

• Combine all glaze ingredients, except milk, in a bowl. Slowly add milk until you reach the desired pourable consistency. Drizzle all over slightly cooled bars.
  1 cup powdered sugar, 2 tablespoons melted butter, 1 teaspoon vanilla extract, ¼ teaspoon cinnamon, 2-3 tablespoons milk