Preheat oven to 350F/180C.

Line an 8 X 8-inch baking pan brownie tray with parchment paper.

Peel and dice the sweet potato and place in a steamer basket. Steam for about 15 minutes until the cubes are soft. Remove from the steamer basket, cool for 15 minutes, drain again and then mash to a smooth puree in a medium bowl. Set aside. 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 packed cups of puree.

In a food processor, add the sweet potato puree, honey or maple syrup, brown sugar, olive oil, almond flour, oat or spelt flour, and unsweetened cocoa powder. Process on high speed for about 30 seconds-1 minute or until all the ingredients are evenly combined. Scrape down the sides of the bowl and pulse again to get everything. You should end up with a sticky brownie batter. Add the chocolate chips and pulse 2-3 times to incorporate into the batter.

Transfer the brownie batter onto the prepared brownie pan. Bake 35-40 minutes or until the top is set. Cool for 10 minutes in the pan then carefully lift the parchment paper out of the pan and transfer to a cooling rack. Cool the brownies for 20-30 minutes on a cooling rack. Slice the brownie into 16 squares and serve.

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.