In a small bowl, stir together non-dairy milk and apple cider vinegar. Let the mixture sit and curdle.
In a medium bowl, sift together flour, cocoa powder, salt, baking soda, and baking powder. Set it aside.
In a large bowl, combine the eggs, granulated sugar, brown sugar, oil, non-dairy milk mixture, and vanilla extract.
Add the flour mixture into the wet ingredients and mix until just combined. Pour in the hot coffee and stir again until a smooth mixture forms. Cover the bowl and let the batter rest for 30 minutes.
While the batter rests, preheat the oven to 340°F (170°C) and grease and line three 6-inch round pans (or two 8-inch round pans) with parchment paper.
Evenly pour the batter into the cake pans and bake for 32-35 minutes. Let the cakes cool in the pan for 10 minutes before taking them out onto a cooling rack to let them cool completely.
Once cooled, wrap each layer with plastic and put it in the fridge or freezer for an hour.
Frosting
In a saucepan, mix together egg yolks and evaporated milk. Add butter, granulated sugar, brown sugar, vanilla, and salt.
Heat it on medium heat while whisking constantly. Once it reaches a boil, continue to whisk for 5 minutes.
Take it off the heat and add the coconut and pecans. Let it cool completely before putting it in the refrigerator for 30 minutes.
Assembly
Slice the domes off of the chilled cake layers to make them flat and even. Each layer should be about an inch tall.
Place one cake layer on a cake stand or plate. Put a third of the frosting on the cake and spread it to the edge using an offset spatula, knife, or spoon.
Place another cake layer on top and spread another third of the frosting on top. Repeat once more, finishing with frosting on top.
Notes
How to make homemade evaporated milk: Put 1⅓ cup (400ml) non-dairy milk in a small pot. Heat it on medium heat, and once it reaches a boil, turn the heat to low and simmer to reduce until you end up with a cup of evaporated milk.Evaporated milk substitute:Canned coconut milk! Make sure it's the kind that comes in a can, as it's thicker.