Chocolate cake with Chocolate Icing

For the cake : Ingredients 3/4 cup Butter   1 1/2 cups Sugar   3 Eggs   2 cups Flour   1 1/2 tsp vanilla essence   8 tbsp cocoa powder   1 cup Milk   2 tsp baking powder  Directions Beat butter till soft & fluffy. Add 1 cup sugar, egg yolk, essence & beat well. ..