Preheat the oven to 350 degrees.
Spray a 6-cavity donut pan with baking spray.
Using a large bowl, beat the butter and oil together until combined.
Whisk in the sugar.
Whisk in the milk, eggs, and vanilla until combined.
Whisk flour, baking powder, cinnamon, salt, baking soda, and nutmeg together in a separate bowl.
Gradually add the dry ingredients to the wet ingredients.
Fold in 1 cup of mini chocolate chips.
Using a piping bag or spoon, fill the donut pan about 3/4 full.
Bake in the oven for 10-12 minutes.
Allow to cool for a few minutes before removing and placing onto a wire rack.