Preheat the oven to 350 degrees and spray a 9x5 loaf pan with nonstick spray or grease it with butter.
In a mixer, beat the butter and sugars until combined.
Add the butter olive oil and mix until just combined.
Add the egg and mix on low until combined.
Add the milk and vanilla and mix again until combined.
Mix the dry ingredients in a bowl.
Add the dry ingredients to the mixer and mix on medium for about 30 seconds until just combined.
Gently mix in the mini chocolate chips with a rubber spatula.
Pour the batter into the loaf pan and bake for 50 to 55 minutes until a toothpick inserted into the center comes out clean.
Let the loaf cool in the pan until warm and enjoy.
Notes
Storage
Store leftovers in an airtight container at room temperature for up to 4 days.
For longer storage, wrap individual slices in plastic wrap and freeze them in an airtight, freezer-safe container for up to 3 months. You can also wrap an entire loaf in a double layer of plastic wrap and a layer of foil and freeze for up to 3 months.
Bring the loaf to room temperature before serving.
General Tips
Be sure to scrape down the mixing bowl with a rubber spatula and mix the batter again until just combined if necessary.
DO NOT overmix the batter. You only need to mix it for about 30 seconds when you add the dry ingredients.
The batter may be lumpy, and that's okay.
Always bring your cold ingredients to room temperature. This makes you less likely to overmix the batter and gives the bread a better rise.