Step 1

In bowl, mix together flour, sugar, salt and soda.

Step 2

In saucepan, mix together peanut butter, water and margarine.

Step 3

Bring to a rapid boil and pour over the flour mixture.

Step 4

Mix together and add the eggs and buttermilk.

Step 5

Pour into greased sheet cake pan. (or 2 - 9x13 pans) Bake at 350° for 20-25 min.

Step 6

Bring margarine, peanut butter and buttermilk to a rapid boil. Add vanilla and powdered sugar.

Step 7

Frost cake while the frosting is still hot.

Step 8

Let cool completely and cut into bars.