Preheat the oven to 350 degrees Fahrenheit and line a 9-inch loaf pan with parchment paper then spray with non-stick cooking spray and set aside.

Whisk the flour, baking powder and salt together in a small bowl and set aside.

Stir the peanut butter, sugar, brown sugar and egg together in a separate large bowl then whisk in the milk until fully incorporated.

Stir in the flour just until combined. (It should still be slightly lumpy, you don’t want to overmix or the bread will be heavy.)

Pour the batter evenly into the pan then bake for 50-55 minutes or until a toothpick comes out clean when inserted into the center of the bread.

Let it cool for 10 minutes before slicing and serving.