1. Combine first 3 ingredients in an 8-inch square glass or ceramic baking dish, stirring until sugar and espresso dissolve.
2. Cover and freeze until partially frozen (about 1 hour). Scrape mixture with a fork, crushing any lumps. Freeze an additional 1 hour and 35 minutes or until completely frozen, scraping entire mixture with a fork every 30 minutes.
3. Scoop mixture into espresso cups or small glasses, and, if desired, top with whipped topping and chocolate-covered espresso beans.