Combine shortening and peanut butter in a small saucepan over low heat. Stir continually until melted. Turn off heat, add vanilla extract, and dump mixture ontop of powdered sugar in a large bowl.
Stir to combine powdered sugar with peanut butter mixture. (It will take some time.) Once fully combined, pat mixture into an 8x8 or 9x9 metal baking pan, and allow to fully cool.
To make cutting easier, chill pan in refrigerator, then cut into very small squares. Fudge can then be packaged in a nice tin layered with waxed paper and given as a gift. Enjoy!