Preheat oven to 350°. Line a loaf pan with parchment paper set aside.
Cream the softened butter and sugars together with a mixer until light and fluffy. Add the eggs and mix to combine, scraping down the sides of the bowl as needed.
Add the pumpkin, milk, vanilla and bourbon if using. Mix on low to combine. The mixture will look a but lumpy but it will come together with the dry ingredients.
Add all dry ingredients, except chocolate chips, and mix until smooth. Stir in the chocolate chips.
Spread batter evenly into the prepared loaf pan.
Bake for 55-65 minutes or until a toothpick or knife inserted into the center comes out clean.