Dulce de leche, which flavors the ice cream here, is a caramel-like candy popular in Latin America.
Process first 3 ingredients, and, if desired, 1 Tbsp. coffee liqueur in a blender until smooth, stopping to scrape down sides. Serve immediately.
Note: For testing purposes only, we used Häagen-Dazs Dulce de Leche and Coffee Ice Creams and Kahlúa coffee liqueur.