Preheat & Prep. To start, preheat the oven to 375 degrees F. Grease an 8 or 9 inch springform pan, or grease an 8 or 9 inch round cake pan. If using a cake pan instead of a springform, cut two long strips of parchment paper and make an "X" on the bottom of the pan. Fold them over the edge of the pan a bit so they don't flop right into your batter. Then, layer in a circle that's been cut to fit the bottom of your pan (I just trace the pan on parchment and cut it out). When the cake has cooled a few minutes on a cooling rack, you'll use the "X" strips as handles to lift the cake out.
Melt Chocolate & Coconut Oil. In a medium microwave safe bowl (or a medium saucepan), melt unsweetened chocolate and coconut oil together over low heat until completely smooth.
Whisk Eggs. While the chocolate is melting, whisk eggs together in a bowl until they are slightly lighter in color. (When you lift your whisk up, the eggs should fall in a thin stream instead of in clumps--this is called the "ribbon test")
Combine. When the chocolate is melted, remove from heat. Stir in maple syrup to cool the chocolate mixture down slightly, then slowly whisk in the eggs. Stir in vanilla extract and salt. Sift in the cocoa powder (to avoid lumps) using a sifter or fine mesh sieve and stir to just combine.
Transfer The Batter. Pour cake batter into your prepared pan, gently shake the pan back and forth a bit to settle the batter, and transfer to the oven.
Bake 15-20 minutes, or until the middle is just set. (if using a 9 inch pan, you'll want to check it at 13-15 minutes as it may cook slightly faster) Remove from oven and allow to cool 5-10 minutes in the pan before transferring out of the pan and onto a cooling rack. If you've used a springform pan, you'll open the ring and allow the cake to finish cooling on the cooling rack that way. If you've used the parchment trick, use the "handles" you made with the parchment to gently lift the cake out and transfer to a cooling rack.
Serve. Enjoy this cake with your favorite toppings, like raspberry sauce, powdered sugar, dairy-free whipped cream, etc. Store leftover cake (without toppings!) in an airtight container at room temperature 1-2 days, in the refrigerator 3-4 days, or freeze up to 2 months.