Brew 1 cup of your favorite coffee and let it cool slightly.
In a small bowl, sprinkle gelatin over 1/4 cup of cold water and let it bloom for 5 minutes.
Heat the brewed coffee in a saucepan over low heat.
Add sugar to the warm coffee and stir until dissolved.
Remove the saucepan from heat and add the bloomed gelatin, stirring until fully dissolved.
Pour the coffee mixture into a square or rectangular dish.
Allow the mixture to cool to room temperature.
Refrigerate for at least 2 hours, or until fully set.
Once set, cut the jelly into cubes or desired shapes.
Serve chilled, topped with whipped cream if desired.