1In bowl mix together flour, sugar and baking soda. Set aside.
2In a sauce pan on medium heat bring almost to a boil the peanut butter, butter and water. When it steams little puffs and tiny bubbles take off the heat.
3Pour into flour mix and mix together. Set aside. Let cool to room temperature.
4In a smaller bowl mix egg, evaporated milk and vanilla. Add to flour mix after it cools. If don't wait for it to cool you will get big chunks of cooked eggs in your cake. Stir until completely mixed.
5Pour into greased 9 x 13 cake pan and bake at 350 degrees for about 30 minutes or until toothpick comes out clean when inserted in the middle of the cake.
6Cool then frost with my Fudge Frosting recipe or something similar.