An easy, make-ahead, dessert for Valentine's Day! As sweet as they look!
- 1/2 cup unsalted butter, room temperature
- 3/4 cup granulated sugar
- 1 large egg + 1 egg yolk
- 2 teaspoons vanilla extract
- 1 and 1/2 cups flour
- 1/4 teaspoon salt
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1 and 1/2 teaspoons cornstarch
- 1 cup rainbow sprinkles
- 3/4 cup unsalted butter, room temperature
- 2 and 1/4 cups confectioners' sugar
- 3 Tablespoons heavy cream
- 1 teaspoon vanilla extract
- food coloring for frosting
- Make the bars: Preheat oven to 350°F. Line an 8-inch or 9-inch square baking pan with aluminum foil, making sure to leave enough overhang on the sides.
- In a large bowl of a stand mixer fitted with a paddle attachment, cream the softened butter for about 1 minute on medium speed. Add the sugar on medium speed until fluffy and light in color.
- Beat in egg, egg yolk, and vanilla. Scrape down the sides as needed.
- In a medium bowl, whisk together the flour, salt, baking powder, baking soda, and cornstarch. With the mixer running on low speed, slowly add the dry ingredients to the wet ingredients in 3 different parts. The dough is quite thick.
- Once combined, gently add in 1/2 cup sprinkles on low speed.
- Press the cookie dough evenly into the prepared baking pan. Bake for 25-26 minutes or until very lightly browned on top. You want the cookie bars to be extra soft, so careful not to overbake. Allow the bars to cool completely on a wire rack at room temperature before frosting. The center will slightly sink.
- Make the frosting: With a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium speed until creamy - about 2 minutes. Add confectioners' sugar, cream, and vanilla extract with the mixer running on low. Increase to high speed and beat for 3 full minutes. Add more confectioners' sugar if frosting is too thin or more cream if frosting is too thick. Beat in food coloring.
- Remove cooled bars from the baking pan using the aluminum foil overhang on the sides. Frost the bars with a thick layer of frosting and decorate with extra sprinkles if desired. Cut into squares. Use a very sharp knife and wipe off with a paper towel between each cut to make neat, even cuts. Store bars in an airtight container at room temperature for up to 2 days and in the refrigerator up to 5.
Make ahead tip: You can make these bars and the frosting 1 day in advance - store the bars, covered, at room temperature overnight and store the frosting, covered, in the refrigerator. Frost before cutting and serving. You can also freeze the unfrosted bars for up to 3 months. Thaw overnight in the refrigerator, frost, cut, and serve.
Adapted from Sally's Baking Addiction.