I feel certain my recipe is the one you are looking for. I was introduced to this candy 40 years ago as a teen at a church social.

Ingredients:
1/2 Cup Cold Mashed Potatoes (no salt, milk or seasoning)
1/8 Tsp. Salt
1/2 Tsp. Vanilla
About 4 Cups Confectioner's Sugar
1/2 Teaspoon Vanilla
1 Cup Peanut Butter

To potatoes add salt and enough sugar to make easily handled fondant: beat well. Add vanilla. Turn half mixture onto board (or wax paper), dusted with Confectioner's sugar. Roll into rectangle, 1/4 inch thick. Spread with 1/3 of peanut butter, then roll up from "short side", jelly roll fashion. Repeat with rest of ingredients.

Chill. Cut into slices 1/4 inch thick. Enjoy! Mary