This is an easy coffee jelly recipe that requires only two ingredients and can be made simply by shaking a plastic bottle. Its appeal lies in its ease of preparation and minimal cleanup. Simply dissolve gelatin in a small amount of coffee in the microwave, pour it back into the plastic bottle containing the remaining coffee, and shake. Chill in the refrigerator for at least 3 hours until set, and it's ready. Pour into glasses and top with ice cream or whipped cream if desired to enjoy a moderately sweet coffee jelly with a bouncy texture and a hint of bitterness. A method using a container that doesn't require a plastic bottle is also introduced, making it a perfect summer dessert recommended even for beginners.