Step 2

Preheat the oven to 350F (180C). Line an 8-inch square baking dish with parchment paper, extending the paper up the sides. Place the chocolate in the freezer.

Step 3

Spread the hazelnuts on a baking tray and toast them in the oven for 10 minutes. Remove them from the oven and let them cool, then rub them in a clean kitchen towel to remove the skins. Reserve a few whole nuts for garnishing the brownies, and place the reset of the nuts in a food processor; grind into a meal. Make sure you don't overprocess. Transfer to a large mixing bowl and set them aside.

Step 4

Place the chilled chocolate in the food processor and grind into the smallest pieces possible. Transfer to the bowl with the ground hazelnuts and add the almond flour, cocoa powder and salt. Stir to mix evenly.

Step 5

Combine the dates, sweet potato chunks and almond butter in the food processor and purée until smooth. Spoon this mixture into the bowl with the ground hazelnuts and chocolate; stir to combine thoroughly.

Step 6

Spoon the batter into the prepared baking dish and even out the top with a spoon. Transfer the dish to the oven and bake for 25 to 30 minutes, until the top of the brownie is firm to the touch.

Step 7

Remove the pan from the oven and let it cool to room temperature, then transfer the brownie to a cutting board, using the parchment paper to lift it out of the pan. Dust the brownie with cocoa powder. Chop the reserved whole hazelnuts and sprinkle them on top, if desired. Slice the brownie into bars.