In a medium bowl, whisk together the tahini and coconut oil until smooth. Add the maple syrup, salt, and vanilla, and stir until creamy. Divide the mixture evenly between two smaller bowls. Whisk the cocoa powder into one of the bowls.

Place the cocoa powder batter into the baking pan (note: I do the reverse of what Mareya does here - I put the cocoa layer first and marbled in the tahini layer on top). Dollop the tahini mixture on top and use a toothpick to swirl the two together and make a marble effect (do not swirl until combined - you want to keep the two parts distinct). Cover and refrigerate for at least two hours, preferably overnight.

Cut the fudge into two-incch blocks and store in the freezer to keep firm.