There are so many versions of this timeless classic but it's hard to say which is the best until you give a few of them a chance. This one just might be as loved by your family as it is by mine.
Preheat oven to 350 degrees F (180 C) and grease 3 9-inch round cake pans with oil. Whisk together butter and sugar until creamed then beat in coconut milk and lemon. Add soda, salt, baking powder, vanilla, and cocoa and stir until smooth. Stir in coffee and flour, then stir in melted chocolate until batter is smooth.
Divide batter among the prepared pans and place in oven. Bake for 35 - 40 minutes until toothpick comes out clean. Remove from oven and allow to cool for about 15 minutes then loosen edges with knife and remove cakes to wire rack to cool completely.
Filling:
While cake is baking, whisk starch and sugar together a medium saucepan with milk and coconut cream until smooth. Bring to a low boil over medium low heat, stirring constantly. Continue stirring as it starts to boil until it thickens enough to coat the back of a spoon, about 5 minutes. Remove from heat and stir in butter until melted and smooth. (If any lumps have formed at this point, pour mix through a fine mesh strainer.) Add vanilla, salt, nuts, and coconut and allow to cool for about 25 minutes before spreading on cake.
Assemble:
Spread filling gently in between layers of cake and on top. Melt chocolate and butter in a double boiler or microwave safe bowl and pour into a pastry bag. You can add the chocolate however you like. I chose to drizzle in a criss-cross pattern over top and then in zig-zags around the edge.
Recipe Notes
If you have trouble finding coconut cream at your local grocery store it's completely fine to use full-fat coconut milk and scrape the cream off of the top. Just be sure that it's cold enough to separate.