Start by preheating your oven to 350°F (175°C). This ensures that your cake bakes evenly.
Grease your 9-inch round cake pan with coconut oil or butter to prevent the cake from sticking. You can also line the bottom with parchment paper for extra protection.
In a double boiler, combine the chopped unsweetened baking chocolate and coconut oil (or butter). Stir constantly until melted and smooth. If you don’t have a double boiler, you can use a microwave, melting in 30-second intervals and stirring in between.
In a large mixing bowl, whisk together the melted chocolate mixture, full-fat canned coconut milk, and pure vanilla extract until well combined.
In a separate bowl, sift together the cocoa powder, sugar-free sweetener, and sea salt. This step helps to avoid any lumps in your dry ingredients.
Add the eggs to the chocolate mixture, one at a time, stirring well after each addition. Make sure they are fully incorporated to achieve a smooth batter.
Slowly add the dry ingredients into the wet mixture, stirring until just combined. Be careful not to overmix; a few lumps are okay.
Pour the batter into your prepared cake pan and spread it out evenly. Bake in the preheated oven for 25-30 minutes or until a toothpick inserted into the center comes out with a few moist crumbs.
Once baked, remove the cake from the oven and let it cool in the pan for about 10 minutes. Then, gently transfer it to a cooling rack to cool completely before serving.