This is an old recipe that my mother found back in the 1950's. It is perfect for Christmas or New Year's. You can use any type of cake mix you like including yellow, white, French vanilla, or a mild chocolate such as Swiss chocolate or German chocolate. We usually use yellow or white cake mix. If you let it chill overnight in the refrigerator, the flavors will blend and it is absolutely heavenly! Note that prep and cooking times do not include cooling times for cake and filling.
Bake cake according to package directions. I usually use yellow or white cake mix, but you can use others too. (See personal notes.) Cool cake completely.
Combine egg, sugar, evaporated milk, salt, and butter in a 2-quart saucepan. Cook and stir over medium heat, stirring constantly, until mixture thickens, about 10 minutes. Do not boil. Mixture should be thick enough when it just begins to boil. Remove from heat.
Stir in vanilla, coconut, pecans, and cherries. Mix well. Cool completely at room temperature, or chill to cool if you are short on time.
When cake and filling are both cool, spread filling between layers and on top of cake (not around sides). If desired, decorate top of cake with additional pecan halves and whole maraschino cherries (drained well). Refrigerate until thoroughly chilled before serving.