Granny Cake

Place baking dish in oven and bake for 40-45 minutes, or until toothpick inserted in center comes out clean.
While cake cooks, combine evaporated milk, sugar and butter in a medium saucepan over medium-high heat and bring to a boil.
Remove from heat and stir in vanilla extract, then pour over hot cake.
Let cake cool so it absorbs icing, then slice, serve and enjoy.