Bring two 14-ounce cans sweetened condensed milk, 1/2 cup brown sugar, 1/2 cup butter and 1 teaspoon vanilla to a boil over medium-low heat. Cook the mixture for three to five minutes, stirring continuously. Once the icing has a texture similar to pudding, remove from heat and let it cool.
For a variation on the quick caramel icing, stir in 1 1/2 cups toasted chopped pecans, 1 1/2 cups sweetened coconut, or a combination of both ingredients, after cooking. To make a different easy caramel icing, melt 1/2 cup butter in a saucepan, then add in 1 cup brown sugar. Boil the mixture over low heat for two minutes while stirring, then mix in 1/4 cup milk. Bring back to a boil while stirring, then allow to cool. Gradually beat in 1 3/4 to 2 cups confectioner's sugar, adding hot water for desired thickness.
Make a buttermilk cake to go with the caramel frosting by creaming together 1 cup butter and 2 1/3 cups sugar. Add three eggs, one at a time, then beat in 1 1/2 teaspoons vanilla. Mix together 3 cups flour, 1 teaspoon baking powder and 1/2 teaspoon baking soda. Gradually add the dry ingredients to the wet ingredients, alternating with 1 cup buttermilk. Bake in a greased and floured 10-inch tube pan for 45 to 50 minutes at 350 degrees Fahrenheit.