In a medium bowl combine all-purpose flour, cocoa (sift this in to get rid of lumps), baking powder and salt. Set aside.

Over low heat, melt butter and stir in sugar and vanilla extract until well combined.

To the butter-sugar mixture add eggs, one at a time. With a wooden spoon vigorously mix in each egg until well-combined.

To the butter-egg mixture whisk in the cocoa mixture until fully combined.

In a microwave safe bowl add Nutella and peanut butter. Heat in the microwave in 20 second intervals until it reaches a runny consistency. Stir this mixture into the batter.

Pour the batter into a glass 9 x 13 pan that has been sprayed with cooking spray. Bake for 30 minutes in a 350 degree oven.

Let brownies cool completely before cutting.