Bake the cake: Preheat oven to 350°F (175°C). Grease and flour a bundt pan. In a large bowl, whisk together flour, cocoa powder, sugars, baking soda, baking powder, and salt. Add eggs, sour cream, milk, oil, and vanilla; mix until smooth. Stir in hot water or coffee. Pour into pan and bake 45–55 minutes or until a toothpick comes out clean. Cool in pan for 10 minutes, then invert onto a wire rack and let cool completely.

1. Make the frosting: In a saucepan, combine evaporated milk, sugar, egg yolks, and butter. Cook over medium heat, stirring constantly, for about 10–12 minutes or until thickened. Remove from heat and stir in vanilla, coconut, and pecans. Let cool to room temperature.
2. Assemble the cake: Once the cake has cooled, spoon the coconut-pecan frosting over the top, allowing it to drip down the sides. Optionally, drizzle melted chocolate and sprinkle with extra pecans or coconut.