Preheat oven to 325°F (163°C). Line an 8-inch or 9-inch square baking pan with parchment paper or aluminum foil, leaving an overhang on the sides to lift the finished brownies out.

Melt the butter, granulated sugar, cocoa powder, and salt in a large bowl in the microwave. Melt in 30 second increments and stir after each time until the butter is completely melted. The mixture will look gritty. Set aside for a few minutes as you get the other ingredients ready. You don’t want the mixture to be piping hot.

Stir in the vanilla extract. Add the eggs one at a time, stirring after each addition. The batter will be thick and look shiny. Add the flour, beating with a whisk until fully combined. Try not to overmix the batter at this point. Gently fold in the peanut butter chips, leaving a few to sprinkle on top. Pour into prepared baking pan and sprinkle with remaining peanut butter chips.

Bake for 25 minutes and check the brownies for doneness. Insert a toothpick inserted in the center. If it comes out with only a few crumbs, the brownies are done. Bake for 3-5 minutes if the brownies look too liquidy. Do not bake over 30 minutes.

Allow the brownies to cool completely before cutting into squares. Brownies remain soft and fresh stored in an airtight container for up to 7 days. They won’t last that long, trust me!