Collect gelatin powder, brewed coffee, sugar, and optionally, flavored syrup or creamer to enhance the taste.
In a bowl, sprinkle gelatin over cold water and let it bloom for 5 minutes until softened.
Brew a strong batch of coffee and sweeten it to taste with sugar or syrup while it's still warm.
In a saucepan, heat the brewed coffee until warm, then add the bloomed gelatin and stir until completely dissolved.
For extra flavor, mix in flavored syrup or creamer according to your preference, stirring until well combined.
Carefully pour the coffee mixture into silicone molds or a shallow dish, ensuring an even layer.
Refrigerate the mixture for at least 4 hours or until completely set and firm to the touch.
Once set, unmold the coffee jelly from the molds or cut it into cubes if using a dish. Serve chilled.