Set it to 350°F (175°C). Grease an 8×8-inch baking dish or line it with parchment paper. (Pro tip: leave a little parchment hanging over the sides this makes lifting the brownies out a breeze.)
If you haven’t already, cook and mash your sweet potato until it’s smooth. No lumps allowed. I like to bake mine ahead of time, but microwaving works if you’re in a pinch.
In a big bowl, stir together the sweet potato puree, peanut butter, honey (or maple syrup), and eggs. Keep mixing until everything is smooth and creamy.
Sprinkle in the cocoa powder, flour, baking powder, and salt. Stir until just combined. No over-mixing otherwise, your brownies can get tough.
Fold in the chocolate chips.
Spread the batter evenly into your prepared baking dish. Bake for 25–30 minutes, or until a toothpick poked in the middle comes out mostly clean (a few fudgy crumbs are perfect).
Let the brownies cool for at least 10 minutes before slicing. This step is harder than it sounds because they smell so good, but trust me waiting makes the slices neater.