Preheat oven to 350°F (175°C). Grease a standard 9"x 5" loaf pan. If you like, line the pan with parchment paper and grease the paper.
Whisk together the flour, baking powder, baking soda, and salt. Set aside.
Using an electric mixer on medium speed, beat the butter, brown sugar, and peanut butter until thoroughly combined. Add the eggs and vanilla, and mix well.
Reduce mixer speed to low. Add the flour mixture in 3 portions, alternating with 2 portions of buttermilk. Mix just until combined.
Stir in the chocolate chips.
Transfer the batter to the prepared pan. Bake 50 to 55 minutes, or until the bread is golden brown and a pick inserted into the center comes out clean.
Cool the bread in the pan on a wire rack for 10 minutes. Then remove the bread from the pan to cool completely.