Preheat oven to 350℉ and lightly grease a mini muffin pan with cooking spray.
In a large bowl, combine the butter and sugar.
1/2 cup butter, 2/3 cup sugar
Stir in the egg and vanilla.
1 egg, 1 teaspoon vanilla
Lastly, add the dry ingredients and mix until a dough is formed.
1 1/3 cups flour, 1/4 teaspoon baking powder, 1/4 teaspoon baking soda, 1/4 teaspoon salt
Roll about 1 1/2 teaspoons of dough (1/2 tablespoon) into a ball and press into the prepared muffin tin. I recommend using a very small cookie scoop (if you don't have a really small cookie scoop, use a cookie scoop that holds about 1 tablespoon of dough, scoop it up and cut the scoop in half).
This recipe will make about 48.
Bake for 10-12 minutes or until outer edges are golden brown; don't over-bake.
Right away, take the lid of a vanilla extract bottle (or something similar sized) and press into the center of each cookie to make a little spot for the filling.
Let cool for 15 minutes before carefully removing from the pan; let cool completely on a wire rack. While you wait, make the filling and prepare the fruit.