Preheat your oven to 350°F (convection) and line an 8×8 inch pan with parchment paper. Bake your sweet potatoes until soft in the center, either by wrapping in foil and baking at 425°F for 60–80 minutes, or by wrapping in damp paper towels, poking holes, and microwaving for about 6 minutes. Once cooked, remove the skins and mash the sweet potatoes until smooth (~600 g).

In a medium-sized bowl, add the mashed sweet potatoes and maple syrup (or honey). Mix together until smooth and well combined.

Add the eggs and egg yolk to the sweet potato mixture. Whisk for 2–3 minutes until the batter is slightly frothy and uniform in color, which helps make the brownies moist and light.

Stir in the vanilla extract until evenly incorporated.

In a separate bowl, combine the blended oats, cocoa powder, and baking soda. Gradually fold the dry ingredients into the wet mixture until a thick brownie batter forms and no dry spots remain.

Fold in the chocolate chips, mixing just until evenly distributed throughout the batter.

Pour the batter into the prepared pan, smoothing the top with a spatula. Bake for 28–32 minutes at 350°F, or until the edges are set and the center is slightly soft.

Let the brownies cool in the pan for 10 minutes before slicing. Cut into 16 squares (4×4). Enjoy immediately or store in the refrigerator for up to 5–7 days.