• Preheat oven to 180°C (350°F).
• Line a brownie tray with parchment paper. I used an 8x8-inch pyrex pan. Set aside.

Prepare the sweet potato puree

• Peel a large orange sweet potato and dice it into small cubes.
• Place the sweet potato cubes into a steamer and cook for 15 minutes or until the cubes are soft and easy to smash into a puree.
• If you don't have a vegetable steamer, you can place the sweet potato cubes in a microwave-safe bowl. Cover it with a plate and microwave 5-6 minutes until soft. Note that microwave cooking will remove the nutritional value of sweet potato. It is not the method I recommend.
• Cool the sweet potato cubes at room temperature. They are ready to be mashed into a puree when no more steam release. It usually takes 10-15 minutes. Discard any water that may be left in the bowl if you choose the microwave method.
• Mash the sweet potato cubes into a puree using a fork or potato masher.
• Carefully weigh 12 oz (350 g) of sweet potato puree or 1 1/3 cup of puree. If you use cups, make sure you pack the puree very well in the cups to ensure the measurement is precise.

Brownie Batter

• In a food processor, add the sweet potato puree, maple syrup, coconut sugar, melted coconut oil, almond flour, oat flour, and unsweetened cocoa powder.
• Blend on high speed for about 30 seconds-1 minute or until all the ingredients are evenly combined. You may have to stop the food processor after 30 seconds, scrape down the sides of the bowl and repeat to ensure that all the ingredients are well combined. It usually takes no more than 1 minute of processing to get a sticky brownie batter.
• Add in chocolate chips and pulse 2-3 times to incorporate into the batter. Keep some chips to sprinkle on top of the brownie before baking if desired.
• Transfer the brownie batter onto the prepared brownie pan. Sprinkle the extra chocolate chips now if you kept some of them.
• Bake 35-40 minutes or until the top is set.
• Cool 10 minutes in the pan then release the brownie from the pan lifting the pieces of parchment paper.
• Cool down for 20-30 minutes on a cooling rack. After that time, I recommend placing the brownie in the freezer 10-12 minutes to cool faster and get the most intense fudgy texture. It will also make the brownie easier to slice without falling apart.
• Slice the brownie into 16 squares. This is optional but you drizzle some melted dark chocolate on top of the brownie before serving, as seen in the picture above.
• Store the brownie in an airtight box in the fridge for up to 4 days. You can store the brownies at room temperature for 2 days.
• Freeze in ziplock bags and defrost the day before.