1.   Beat until smooth and of spreading consistency.

2.   Beat until cool and of spreading consistency.

3.   Add oil until peanut butter is of spreading consistency.

4.   Add a few drops of milk if needed to reach spreading consistency.

5.   Add remaining milk and beat to desired spreading consistency.

6.   Add vanilla and continue beating until spreading consistency.

7.   Add the sour cream, a little at a time, and whisk until of spreading consistency.

8.   By the teaspoonful, add milk to bring mixture to an easy spreading consistency, being careful not to make it too runny.

9.   Chill until mixture thickens to spreading consistency.

10.   Cool to spreading consistency.