Preheat oven to 350 degrees F (175 degrees C). Grease and flour two 9 inch round baking pans.
In a large bowl, cream together the butter and 2 cups of sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla. Combine flour, baking powder, baking soda and salt; stir into the batter alternately with the milk. Divide batter evenly between the prepared pans.
Bake in preheated oven for 30 to 35 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool in pans for 10 minutes, then turn out onto a wire rack and cool completely.
To make the frosting: In a medium bowl, cream together the butter, confectioners' sugar, vanilla and 2 tablespoons of milk until light and fluffy. Beat in additional milk, 1 teaspoon at a time, until desired consistency is reached. Spread frosting over cooled cake.
Interesting Facts
This cake is also called a "silver wedding cake" because of its traditional white color.
The cake is often decorated with edible silver dragees.
The frosting can also be tinted with food coloring to achieve other colors.