Preheat your oven to 350°F (175°C). Lightly grease a muffin tin or mini tart pan to ensure your cookie cups release easily after baking.
In a large bowl, beat the softened butter, brown sugar, and granulated sugar together until creamy and fluffy, about 2-3 minutes.
Mix in the eggs one at a time, beating well after each addition. Stir in the vanilla extract.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. Gradually add this dry mixture to the wet ingredients, mixing just until combined.
Gently fold in the semi-sweet chocolate chips, distributing them evenly throughout the dough.
Scoop about 2 tablespoons of dough into each muffin cup. Press the dough up and around the sides to form a cup shape, leaving the center hollow.
Bake for 10-12 minutes until the edges are golden but the centers remain soft. They will firm up as they cool.
Allow the cookie cups to cool in the pan for 5 minutes before removing them to a cooling rack. Let cool completely to hold their shape.