Preheat the Oven:
Preheat your oven to 350°F (175°C). Grease a mini muffin tin with non-stick spray or butter.

Prepare the Cookie Dough:

• In a medium bowl, whisk together flour, baking soda, and salt. Set aside.
• In a large mixing bowl, beat butter, brown sugar, and granulated sugar until light and fluffy.
• Mix in the egg and vanilla extract until well combined.
• Gradually add the dry ingredients, mixing until just combined.
• Fold in 3/4 cup chocolate chips.

Make the Peanut Butter Filling:
In a small bowl, mix peanut butter and powdered sugar until smooth.

Assemble the Cookie Cups:

• Scoop about 1 tablespoon of cookie dough into each mini muffin cup.
• Use your thumb or a spoon to press a small indent in the center of each dough ball.
• Fill each indent with 1 teaspoon of the peanut butter mixture.
• Place a small piece of dough over the peanut butter filling or slightly pinch the edges to cover.
• Sprinkle the remaining 1/4 cup chocolate chips on top.

Bake:
Bake for 10-12 minutes, or until the edges are golden brown.
Let the cookie cups cool in the muffin tin for 5 minutes, then transfer to a wire rack to cool completely.