Peanut butter brownies are rich and fudgy brownies stuffed with a layer of creamy peanut butter filling. Top these easy and chewy stuffed brownies with swirls of peanut butter.
Heat 1 cup of peanut butter just enough so that it is pourable. Pour the peanut butter into the prepared pan and transfer to the freezer to set for at least 30 minutes and up to 1 hour.
Once the peanut butter is frozen, remove the layer from the pan and return it to the freezer until the brownie batter is prepared. Preheat the oven to 350 F (177 C). Line an 8x8 pan with parchment paper along the bottom and two sides.
In a microwave safe mixing bowl add the butter and ½ cup (85 g) of chocolate chips. Heat in 30 second increments, stirring after each until the butter and chocolate are fully melted and mixed together.
Whisk the in the granulated sugar and light brown sugar into the still warm melted butter and chocolate. Heat the mixture for one additional minute and whisk again until fully combined.
Whisk in the eggs, egg yolk, vanilla extract and cocoa powder and salt until smooth and glossy. Whisk in the flour until well combined. Fold in the reserved chocolate chips if using in the brownies.
Evenly scoop half of the brownie batter into the prepared pan. Remove the frozen peanut butter layer from the freezer. Gently lay the peanut butter layer on top of the brownie batter and gently pull the parchment paper off the peanut butter. Top with the remaining brownie batter and remaining ¼ cup peanut butter.
Bake for about 45 - 50 minutes or until a toothpick inserted into the center comes out with a few moist crumbs. Cool the brownies in the pan for 30 minutes. Lift the brownies from the pan to fully cool on a cooling rack. Slice the brownies and enjoy!