Cook the Base: In a medium-sized saucepan, combine the evaporated milk, egg yolks, butter, sugar, and brown sugar. Place the saucepan over medium heat and bring the mixture to a boil, then lower the heat to a simmer. Stir frequently and continue cooking for 10-12 minutes, or until the mixture has thickened. Remove from the heat.
Add Mix-Ins: Stir in the shredded coconut, chopped pecans, and vanilla.
Frost & Chill: Let the frosting cool slightly, then spread it evenly over the cooled cake. Chill the cake for 1-2 hours before serving to allow the frosting to set.

Enjoy this classic chocolate treat!