Preheat the oven to 350°F (175°C) and grease a standard 12-cup muffin tin with non-stick spray.
In a stand mixer or large bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy, approximately 3 minutes.
Add the egg and vanilla extract, beating until the mixture is smooth and fully emulsified.
In a separate bowl, whisk together the flour, baking soda, and salt to ensure even distribution of leavening agents.
Slowly incorporate the dry ingredients into the wet mixture, mixing on low speed until just combined.
Fold in the chocolate chips using a spatula to prevent over-mixing the dough.
Distribute the dough evenly into the 12 muffin cups, pressing down slightly to form a flat top in each cavity.
Bake for 10 to 12 minutes until the edges are golden brown but the centers still appear slightly soft and underbaked.
Remove from the oven and allow the cups to cool in the pan for at least 15 minutes to allow the gooey centers to set before removal.