Preheat your oven to 350°F (175°C).

In a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until smooth. Add in the egg and vanilla extract, mixing until fully combined.

In another bowl, whisk together the all-purpose flour, rolled oats, baking soda, and salt.

Gradually add the dry mixture to the wet mixture, stirring until just combined. Be careful not to overmix.

Gently fold in the semi-sweet chocolate chips, distributing them evenly throughout the dough.

Using a spoon or cookie scoop, drop rounded tablespoons of dough onto a lined baking sheet, leaving space between each cookie for spreading.

Bake in your preheated oven for 10-12 minutes, or until the edges are golden brown and the centers still look slightly soft.

Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack.