Preheat your oven to 350°F (175°C).
Grease your 9x13-inch baking dish or line it with parchment paper.
In a large mixing bowl, combine the softened salted butter and creamy peanut butter. Cream together until smooth.
Add packed brown sugar and granulated sugar to the butter mixture. Mix until fluffy.
Crack in the eggs one at a time, mixing well after each addition, then add the vanilla extract.
In a separate bowl, whisk together flour, baking powder, and salt. Gradually add this to the wet ingredients until just combined.
Fold in the peanut butter chips until evenly distributed.
Pour the batter into the prepared baking dish and spread evenly. Bake for 25-30 minutes.
Remove from oven and let cool in the pan for 10-15 minutes before transferring to a wire rack to cool completely.
