Step 1

Preheat oven to 350F (176C) and prepare an 8×8 (20x20cm) baking pan by lining it with a sheet of aluminum foil, leaving a few inches of overhang on the sides to allow for easy removal. Grease the foil and set aside.

Step 2

Add coconut oil and chocolate chips to a small saucepan set over low heat. Stir until oil and chocolate have melted before removing from heat and setting aside to cool slightly.

Step 3

Using a handheld mixer or a stand mixer fitted with the whisk attachment, beat together eggs, sugar, and vanilla extract until smooth and pale, about 2 minutes. Add melted chocolate mixture and mix until well combined. Reduce speed to low and add cocoa powder, arrowroot powder, and salt, mixing until well combined and scraping down the sides of the bowl as necessary. Batter should be thick and smooth.

Step 4

Pour batter into prepared pan, spreading it evenly with a greased spatula. Bake for 25-30 minutes, until centre is set. Remove from oven and let cool in pan for about 15 minutes before removing and transferring to a wire rack to cool completely. Cut into squares and serve.