Combine Currants, Hot Water and Rum Extract in a small bowl; let stand for 1 hour.
Cream Butter and Sugar together. Add Egg and beat till light and fluffy.
Stir in Currant mixture and Flour.
Drop flour in tiny mounds onto a greased cookie sheet. (Emphasis on TINY - these are supposed to be about the size of a penny after baking - Mounds should be about the size of a small grape).
Bake at 425`for 5 Minutes (or until edges are golden).