In a medium saucepan on medium heat bring the butter, water, and cocoa powder for the cake to a boil, stirring with a whisk.  Pour this mixture in the bowl with the flour and sugar and mix with a hand mixer (you can also use a stand mixer, I prefer a hand mixer with this recipe).  You just need to mix until blended together.

In a bowl or measuring cup mix your cake milk, vanilla, baking soda and eggs with a fork until blended.  Pour this into the large bowl.  You can stir by hand, or mix with your mixer until all is blended together.

Bake for 25-30 minutes, depending on your oven.

The frosting needs to go on the cake when it is still hot.  I usually wait until I have about 5 minutes left for the cake to cook before I start the frosting.  You want both the cake and frosting to be warm. 

In the same saucepan you used for the cake, heat the butter, milk and cocoa powder over medium heat.  Stir constantly until it comes to a boil.  Remove from heat and add the vanilla.  Slowly add the powdered sugar (I usually do it a cup at a time), and mix with your hand mixer until all is blended smoothly.  It will be thick and creamy.  By now your cake should be ready.  Remove cake from the oven, then add your frosting.  It should be easy to spread evenly across your cake.  Let cake cool.  It’s okay to eat it while it is still warm, it will taste delicious!