Combine evaporated milk, sugar, egg yolks, butter and vanilla in a saucepan
Cook over medium heat, stirring constantly, until mixture thickens, about 12 minutes
Remove from heat
Stir in coconut and pecans
Stir until cool and of spreading consistency
Using 2 8 or 9 inch German Chocolate layer cakes, spread one third of the mixture of one layer, top with second layer and spread remaining icing on top of the stacked cake, allowing to drip down the sides.