In heavy saucepan (2 quart), combine sugar, evaporated milk, stick of butter, vanilla and egg yolks. Blend well. Slowly heat up until butter is melted. Cook over medium heat for about 10 minutes or until thickened and bubbly, stirring constantly. Stir in coconut and pecans. Remove from heat.
Reserve 1 1/4 cups of topping (set aside). Add 2 Tbsp.butter to remaining warm topping. Stir until butter is melted. Add dry Pillsbury Plus German Chocolate cake mix until thoroughly moistened.
Shape dough into 1" balls. Place 2" apart on ungreased cookie sheet.
Make indention in the center of each ball with your thumb. Fill each with reserved topping.
Bake at 350 for 13 minutes. Do not over bake. Use wax paper between layers of cookies when storing.
Notes
Note: It is recommended that you do not substitute the cake mix, as results may vary.