Preheat the oven to 350°F. Prepare 2 cookie sheets lined with parchment paper.
Sift the flour into a large mixing bowl. Then, mix in the baking powder and salt.
1 ½ cup all purpose flour, ½ teaspoon baking powder, ¼ teaspoon salt
In the bowl of a stand mixer, cream the butter and sugar together. Beat the room-temperature butter and sugar on high speed until the mixture is light and fluffy.
½ cup unsalted butter, ½ cup granulated sugar
Add the egg, egg yolk, vanilla, and almond extract and beat on high for 1 minute.
1 ½ teaspoon vanilla extract, 1 egg, 1 egg yolk, ½ teaspoon almond extract
Mix the dry ingredients into the wet ingredients on low speed. The dough will be thick and slightly sticky.
Fold the rainbow sprinkles into the cookie dough with a rubber spatula.
¼ cup rainbow Jimmies sprinkles
Use a large cookie scoop to scoop large cookie dough balls. Place 6-8 balls on each cookie sheet and press down on each firmly.
Bake 1 cookie sheet at a time for 10-12 minutes each. Bake until the edges are slightly golden and the cookies seem set.
Top the cookies with extra sprinkles when they finish baking. Let the cookies sit on the baking sheet for 5 minutes before transferring to a cooling rack.