PLACE THE TOFU IN A FOOD PROCESSOR OR BLENDER. PUREE UNTIL CREAMY, ABOUT 30 SECONDS, SCRAPING DOWN THE BOWL ONCE OR TWICE. FOLD IN THE COCOA AND ESPRESSO POWDER. PUREE UNTIL WELL BLENDED, SCRAPING DOWN THE BOWL AS NEEDED. ADD THE SYRUP, VANILLA, MELTED CHOCOLATE, AND OPTIONAL LIQUEUR. PUREE UNTIL SMOOTH.