Preheat the oven to 325° and line your baking sheets with parchment paper.
Add the butter and brown sugar to the bowl of your stand mixer (or use a hand mixer) and beat on medium speed until the mixture is light and fluffy, around 2 minutes.
Add the egg and vanilla and beat for another minute.
Add the flour, sprinkle on the baking soda, baking powder, and salt. Mix until combined.
Add the oats and combine.
Add the chocolate chips and stir until they are just mixed in.
Use a cookie scoop to make balls from 1 tablespoon of cookie dough each and place on prepared cookie sheet 2 inches apart.
Bake for 9 to 11 minutes until the edges begin to brown and the centers are set. Transfer to a wire rack and let cool completely.
Notes
I like to use old-fashioned rolled oats for this recipe but feel free to use quick or minute oats if that's what you have on hand. The texture will be less "toothsome" or chewy but they will still be delicious.
Use whatever chocolate chips you like or have on hand. You can use dark, semi-sweet, milk, mini, or even something like a mint chocolate chip if you like. The choice is yours. I like half milk and half semi-sweet in this recipe.
These cookies freeze well! I like to bake the whole batch and save half of the baked cookies in freezer bags for another day. Just let the frozen cookies come to room temperature before serving (though they are delicious cold, too!).
You can easily replace the chocolate chips with raisins, dried cranberries, or nuts like walnuts or pecans for a different twist.