Preheat your oven to 350°F (175°C). Line a 9×13-inch pan with parchment paper. Set aside.
In a large bowl, beat the softened butter and granulated sugar until light and fluffy. This usually takes about 3 to 5 minutes.
Next, add in the egg, egg yolk, vanilla extract, and almond extract. Beat until well combined.
In a separate bowl, whisk together the flour, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Spread the cookie dough evenly into the prepared baking pan.
Bake for 20 to 25 minutes, or until the edges are lightly golden and a toothpick inserted in the center comes out with a few moist crumbs.
Allow the bars to cool completely in the pan.
In a large bowl, beat the softened butter until smooth and creamy.
Gradually add in the powdered sugar, mixing well after each addition.
Add the vanilla extract, salt, and 1 tablespoon of milk, and beat until the frosting is light and fluffy.
Once the cookie bars are completely cool, spread the frosting evenly over the top.
Add sprinkles if desired. Cut into bars and serve. Enjoy!
