serves 2–4
Put ¼ cup water in a small bowl and sprinkle gelatin on the surface. Set aside to soften.
Place coffee and sugar in a saucepan and heat, whisking, until sugar is dissolved. Remove from heat. Whisk in the softened gelatin. Let cool a few minutes then pour into a flat bottomed dish. A pan closer to 5- by 7-inches will yield cubes, but any dish or container 8x8 or smaller will work.
Chill in refrigerator for 8 hours or overnight. Cut into cubes with a sharp knife, lift out individually with a thin blade or spatula, and serve in small bowls with a splash of sweetened cream or sweetened condensed milk.