Nonstick cooking spray
1 1/2 cups all-purpose flour
1/8 teaspoon fine salt
1/2 teaspoon baking powder
1/2 cup butter, melted and cooled
1/2 cup brown sugar
1/2 cup granulated sugar
1 large egg
2 teaspoons vanilla extract
3 tablespoons rainbow sprinkles, plus more for topping Vanilla ice cream
Preheat oven to 350ºF and grease a muffin tin with nonstick cooking spray.
In a small bowl, whisk together flour, salt, and baking powder and set aside.
In a large shallow bowl, using a rubber spatula, briskly stir together butter and both types of sugar until a thick paste forms. Add the egg and vanilla and stir until incorporated.
Slowly add the dry ingredients into the wet ingredients and keep mixing until just combined and a dough is formed. Stir in sprinkles.
Using an ice cream scoop or large spoon, scoop the dough into the muffin tin. The dough should fill each cup about 3/4 full. This recipe makes about 9 cups.
Bake the dough for about 15 minutes or until just brown around the edges but still soft in the center. Remove from the oven, and using a greased spoon or deep 1/4-inch measuring cup, create wells in each cookie cup, leaving about a 1/4-inch edge around.
Return the cups to the oven and bake for an additional 5 minutes or until the cookie is golden brown.
If any dough has risen in the center of the cookie during the second baking process, simply press down before the cup cools.
Allow the cups to cool completely in the muffin tin. Once cool, use a dull knife to ease the cups out of each well. Store in an airtight container for up to 2 days, and when ready, serve with vanilla ice cream and additional sprinkles.