Preheat your oven to 350°F (175°C). Lightly grease two 8-inch round cake pans. For easy removal, line the bottoms with parchment paper and grease the paper too.
In a large bowl, whisk together your coconut flour, granular sweetener, cocoa powder, protein powder, baking powder, and salt until everything is well combined.
Stir in the eggs, melted butter, and vanilla extract until your mixture is smooth.
Gradually mix in the cooled coffee (or water), about ¼ cup at a time. You're looking for a thick batter that’s easy to spread in the pans, not too runny.
Divide the batter evenly between your two prepared pans and gently spread it to the edges. Bake for 20 to 25 minutes, or until the tops feel just firm to the touch. Be careful not to overbake!
Let the cakes cool in their pans for a short while, then carefully invert them onto a wire rack to cool completely.
In a small bowl, sprinkle gelatin over the water and whisk briefly. Heat in the microwave for about 30 seconds, then whisk again until the gelatin is fully dissolved. Let it cool for 10 minutes.
In a large bowl, combine the heavy whipping cream, powdered sweetener, and vanilla extract. Start beating on high speed, slowly pouring in the cooled gelatin mixture. Continue beating until your cream holds beautiful, stiff peaks.
Place one cooled cake layer on your serving platter. Gently spread all of the creamy filling evenly over the top.
Carefully place the second cake layer on top of the filling. Press down lightly so the cream filling comes to the edges.
Transfer your cake to the freezer for about 30 minutes. This helps the filling set nicely and makes the next step much easier.
In a medium saucepan over medium heat, combine the heavy whipping cream and powdered sweetener. Bring it to a gentle simmer, then immediately remove from heat.
Add the finely chopped unsweetened chocolate and vanilla extract to the hot cream. Let it sit undisturbed for 5 minutes, then whisk until it’s perfectly smooth and glossy.
Allow the ganache to cool for another 5 to 10 minutes to thicken slightly. Slowly pour it over the chilled cake. You can use an offset spatula to spread it over the sides, or simply let it drip down for a lovely rustic look.
Let the glaze set for about 20 minutes before slicing into your delicious, healthy Keto Ding Dong Cake!