Preheat oven to 350°F.
Line an 8" x 8" pan with parchment paper
In a blender, combine black beans, 3 eggs, vanilla, salt, cocoa powder, baking powder and baking soda. Blend until there are absolutely no lumps.
In a bowl, whip until smooth, by hand or with electric beater, honey and coconut oil. Add 2 eggs and whip until smooth.
Pour honey mixture into blender with bean mixture and blend until incorporated. At this point, the batter should look glossy and smooth and very much like any traditional chocolate cake batter.
Pour batter into pan. Thump tin on the counter to smooth batter and dissipate air bubbles.
Bake for 18-22 minutes or until toothpick inserted comes out clean.
Cool on wire rack.