SMALL amounts of warm water, too much will result in a sugary soup
1/2 tsp vanilla or nut extract, banana works too
chopped nuts and other goodies are optional
Directions
Make a dough with the powdered sugar, vanilla, butter and water (like pie dough). Roll the dough about 1/4 in thick between two pieces of wax paper sprinkled with powdered sugar. Generously spread the peanut butter on the dough, trim the ends and roll it up using the wax paper. Chill until firm, cut into slices and serve.
You should cover it with plastic wrap to keep the powdered sugar from drying out. You can make this look hard to prepare like crisped rice cakes ;-)