I adapted this from Our Best Bites, and I have to say--it is really, really good. Or at least this batch was/is. I hope it works out again.
Preheat oven to 350 degrees. Grease an 11 x 17 inch jelly roll pan (a cookie sheet with sides).
Combine 1/2 C butter, 1/2 C coconut oil, 2 ounces baking chocolate, and 1 C water in a small saucepan. Heat until chocolate is melted. Add in 1/4 C cocoa powder; stir until well mixed.
In a small bowl, combine 2 C flour and 1 t baking soda.
In a large mixing bowl, combine 1 C coconut sugar, 1 C agave, 1/2 C buttermilk (or sour raw milk, as I used), 2 eggs, 1 generous t cinnamon, and 1 t vanilla. Combine with chocolate mixture. Add flour mixture and mix very well. Pour into pan and bake 15-20 minutes or until a pick comes out clean. (You want it to look set but still moist.) Five minutes before cake is done, making frosting.
Combine 6 T milk, 2-3 ounces baking chocolate, 1/2 C coconut oil, 1/4-1/2 C agave (sweeten to taste), 1/4 t salt (salt to taste), and 1 t cinnamon in a medium-large saucepan. Heat until bubbles form around the edge. Remove from heat and add 1 C (approx) of finely shredded or grated unsweetened coconut and 1 t vanilla. Stir until well mixed. While icing is still warm, pour over cake.
Definitely serve with milk. (Or vanilla ice cream!)