01 - Pour 1/2 cup of the fruit juice into a medium saucepan. Sprinkle the gelatin powder evenly over the surface and let it sit undisturbed for 5 minutes until it softens and becomes slightly thickened.
02 - Place the saucepan over low heat and stir continuously until the gelatin dissolves completely. Do not allow the mixture to boil, as high heat can weaken the setting power.
03 - Remove the pan from the heat. Stir in the remaining fruit juice, collagen peptides, honey or maple syrup if using, and the lemon juice. Whisk until the collagen has fully dissolved and the mixture is smooth and uniform.
04 - If using diced fresh fruit, gently fold the pieces into the jelly mixture until evenly distributed.
05 - Pour the mixture into silicone molds or a parchment-lined 8x8-inch baking dish. Transfer to the refrigerator and chill for at least 2 hours, or until the jelly is firm to the touch.
06 - If using a baking dish, cut the set jelly into bite-sized cubes. Gently pop the jellies out of the molds and serve immediately.