Peel pre-roasted sweet potatoes (excellent use for leftovers!) and mash the flesh. For a smoother texture, blend flesh in a food processor.

Preheat oven to 350°F. Grease an 8x8-inch baking pan and line with parchment paper, leaving overhang on two sides for easy lifting.

In a small bowl, whisk together the peanut butter powder and water until smooth and paste-like. This ensures it blends evenly into the batter without any dry pockets.

In a large bowl, combine the mashed sweet potato, maple syrup, peanut butter paste, coconut oil, vanilla extract, and eggs. Stir vigorously until smooth and fully combined.

Sift in the cocoa powder, baking powder, and salt directly into the wet mixture. Fold together until just combined and no dry streaks remain - don't overmix. Fold in most of the chocolate chips, reserving a small handful for the top.

Pour the batter into the prepared pan and spread evenly - it will be thick. Scatter the reserved dark chocolate chips over the top. Bake at 350°F until the edges are set, and the center is just barely firm to the touch. A toothpick should come out with a few moist crumbs, not wet batter.

Let the brownies cool in the pan for at least 20 minutes before lifting out using the parchment overhang. Cool further on a wire rack before slicing into 8 squares. They firm up beautifully as they cool - don’t rush it!