Preheat your oven to 350°F (175°C). Lightly grease an 8x8-inch baking dish or line it with parchment paper so the brownies lift out easily after baking.
If not already prepared, cook the sweet potato until tender, then mash it until completely smooth with no lumps. Let it cool slightly before adding to the batter.
In a large mixing bowl, combine the sweet potato puree, peanut butter, honey or maple syrup, and eggs. Stir until the mixture looks smooth and evenly blended.
Add the cocoa powder, flour, salt, and baking powder to the bowl. Mix gently until just incorporated and no streaks of flour remain. Fold in the white chocolate chips so they are evenly distributed throughout the batter.
Spread the batter into the prepared baking dish, smoothing the top with a spatula so it bakes evenly.
Bake for 25 to 30 minutes, checking near the end. The brownies are done when the center is set and a toothpick inserted comes out clean or with a few moist crumbs.
Allow the brownies to cool in the pan for about 10 to 15 minutes before transferring them to a wire rack. Let them cool completely before slicing into squares.
