Preheat oven to 350°F (175°C). Grease a mini muffin tin or line with paper liners.
In a large bowl, cream together the butter, brown sugar, and granulated sugar until light and fluffy.
Mix in the egg and vanilla until smooth.
In a separate bowl, whisk together flour, baking soda, and salt.
Gradually add dry ingredients to wet mixture and mix until combined.
Stir in the mini chocolate chips.
Scoop about 1 tablespoon of dough into each muffin cup and gently press to flatten and create a slight well.
Bake for 10–12 minutes or until edges are golden and centers are just set.
While warm, press down the center of each cookie cup with the back of a spoon to form a deeper well.
Cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
Once cooled, pipe or spoon frosting into the center of each cookie cup.
Top with red, white, and blue sprinkles and other festive decorations.