Preheat oven to 350 degrees. Grease a donut pan with non-stick cooking spray.
In a mixing bowl, add butter and brown sugar. Mix on medium until light and fluffy.
Add in the egg, milk, and vanilla. Mix on low until combined.
Add in the flour, baking powder, and baking soda. Mix on low until the flour is almost combined and turn the mixer to medium and let it mix for a minute.
Stir in the mini chocolate chips with a spatula.
Place the batter into a disposable piping bag or a large ziploc bag. Cut off the tip of the disposable bag or a corner of the ziploc bag.
Fill each donut shape half full. If you over fill it, it will completely cover the center cutout.
Bake for 8 to 9 minutes or until the edges begin to get golden brown.
Let the donuts cool for about five minutes and then turn them out onto a cooling rack. If they stick any, run a toothpick around the hole and outside of the donut. That should help.
Notes
To store any leftover baked chocolate chip donuts, place in an air tight container and store at room temperature for up to 3 days.