Preheat oven to 350°F (177°C). Line the bottom of a 7 inch springform pan with parchment paper.
In a bowl, cream together honey and coconut oil. Mix in the egg yolks (or 2 large eggs).
Add to the mixture coconut milk, cocoa powder, vanilla, cream of tartar, baking soda and salt. Mix until smooth.
Pour the mixture into the spring form pan. Bake for 25–30 minutes. The cake is done when a toothpick is inserted and comes out with moist crumbs. (You want a dense cake when finished so the toothpick should not come out clean.)
Let the cake set for at least 5 hours before cutting and serving.
Serve plain or with a recipe of Double Double Caramel Sauce (also in the book)