Let the leftover coffee cool down, then pour the black coffee into an ice cube tray. Keep them in the freezer, and any time you crave iced coffee — spiked or not — you’ve got these ice cubes at the ready.

To make this Upside-Down Iced Irish Coffee, add the cubes to a clean glass and top with the ounce of Bailey’s. Fill the glass with milk and wait a few minutes for the ice to melt before you take a sip. As the ice cubes melt, they will infuse the milk with rich, coffee flavor. Sip slowly, because the ice cubes will make the drink stronger as you drink — not weaker, like regular ice.