Preheat the oven to 425°F. Line a half-sheet baking sheet with parchment paper, using enough that it hangs over the edges slightly.

In a medium bowl, whisk together the flour, sugar, baking powder, baking soda and salt.

In a larger bowl, whisk together the buttermilk, peanut butter, eggs, and vanilla until it is well combined and the peanut butter is completely incorporated.

Stir in dry ingredients until just moistened.

Pour/scrape the batter into the prepared pan, spreading it out to fill the pan.

Sprinkle with chocolate chips.

Bake 12-15 minutes, until puffy and cooked through.

Remove from the pan using the sides of the parchment to lift. Cut into squares (a pizza cutter works great) and serve with butter, chocolate or maple syrup, if desired.