1 C butter or margarine (2 sticks...This was a little much, I thought. It puddled on top of the first batch. So for the second batch, I used 1 3/4 sticks.)
1 C crunchy peanut butter (There are about 2 cups in a large jar, so you can double this recipe to use the whole jar.)
1 t vanilla
1 pound confectioner's sugar (About 1/2 bag)
Prepare an 8 x 8 square pan by coating it with butter. (I used Pam.) Place butter and peanut butter in a microwave safe bowl and cook on high for 2 minutes.
Stir together and return to microwave to cook 2 additional minutes.
Add vanilla and powdered sugar to the mixture and combine with a wooden spoon. Pour into the prepared pan and spread evenly.
Place a sheet of wax paper over the top and refrigerate until cooled. Cut and serve.