In a medium bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt. Set aside.
Mix Wet Ingredients:
In a large bowl, beat peanut butter with both sugars until smooth and creamy. Add eggs, oil, and vanilla extract, mixing until fully combined.
Combine Wet and Dry:
Stir in the dry ingredients alternately with the buttermilk, mixing just until incorporated. Do not overmix.
Add Chocolate Chips:
Fold in chocolate chips, reserving a handful to sprinkle on top.
Prepare Pan and Bake:
Pour batter into a greased and lined 9×5-inch (23×13 cm) loaf pan. Smooth the top and sprinkle with the reserved chocolate chips. Bake at 350°F (175°C) for 50–60 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
Cool and Serve:
Cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Slice and enjoy!
Serving and Storage Tips
