Vanilla Cookie Bars

Cookie Ingredients

  • 1 1/2 cups all-purpose flour
  • 1/4 tsp salt
  • 1 tsp baking powder
  • 1/2 tsp baking soda
  • 1 1/2 tsp cornstarch
  • 1/2 cup unsalted butter, room temperature
  • 3/4 cup granulated sugar
  • 1 large egg and 1 large egg yolk
  • 2 tsp pure vanilla extract
  • 1/2 cup rainbow sprinkles (not nonpareils)

Cookie Instructions

  1. Preheat oven to 350°F.
  2. Line an 8-inch square pan or 9-inch square pan with aluminum foil.
  3. In a medium bowl, whisk together the flour, salt, baking powder, baking soda, and cornstarch.
  4. In a large bowl, cream the butter on medium speed until smooth, about 1 minute.
  5. Mix in the sugar until fluffy and light in color.
  6. Mix in the egg, egg yolk, and vanilla.
  7. On low speed, slowly mix in the dry ingredients.
  8. Gently fold in the sprinkles.
  9. Press the cookie dough evenly into the prepared baking pan.
  10. Bake for about 25 minutes, or until very lightly browned on top. The cookie should be extra soft. Place on a rack to cool. The center will slightly sink.

Frosting Ingredients

  • 3/4 cup unsalted butter, room temperature
  • 2 1/4 cups powdered sugar
  • 3 Tbsp heavy cream or half-and-half
  • 1 tsp pure vanilla extract
  • Salt

Vanilla Instructions

  1. In a large bowl, beat the butter on medium speed until creamy, about 2 minutes.
  2. Add the powdered sugar, heavy cream (or half-and-half), and vanilla extract on low speed.
  3. Beat for 3 minutes on high speed. Add more powdered sugar if too thin or more cream if too thick. Add a pinch of salt if frosting is too sweet.

Final Ingredients

  • Nonpareil rainbow sprinkles
  • Heart rainbow pastel sprinkles

Final Instructions

  1. After cookie has completedly cooled, remove from baking pan and evenly cover with a thick layer of the vanilla frosting.
  2. Cut into squares.
  3. Decorate with nonpareil and heart sprinkles.