Step 1

Bake cake according to package directions for 2 (9-inch) round cake pans. Let cool.

Step 2

In a medium saucepan over medium heat, combine sweetened condensed milk, butter, and vanilla. Cook about 5 minutes, or until thickened, stirring occasionally. Stir in pecans and coconut.

Step 3

Place one cake layer flat side down on a serving platter. Spread half the coconut mixture on top. Top with second cake layer and remaining coconut mixture.

Step 4

In a small microwaveable bowl, microwave frosting 10 to 15 seconds, or until slightly thin. Drizzle over top and sides of cake. Store cake in refrigerator.