Preheat oven to 375F. Grease a 10inch cake pan.Put a side.
Place the flour, sugar and cocoa in a mixing bowl. Stir well until all mix together. Make a hole in the dry mix with your hand. On that hole add eggs, oil, coconut milk and vanilla. Stir well until you get an uniform batter. Finally add the hot water. Mix well. (the batter is going to be thin).
Pour the batter on a well grease cake pan (10in). Bake for 40 to 45 minutes depends on your oven.
*Chocolate buttercream frosting- beat butter, sugar ,cocoa and vanilla until you get a creamy frosting(u can vary the vanilla with the same amount of amarretto,coconut extract or black coffee