01 - Pour the fruit juice and lemon juice into a small saucepan. Sprinkle the powdered gelatin evenly over the liquid surface and allow it to bloom for 3 to 5 minutes.
02 - Place the saucepan over low heat and stir gently until the gelatin has fully dissolved. Do not allow the mixture to boil.
03 - Remove from heat. Stir in the collagen peptides powder, honey or maple syrup, and vanilla extract if using, until completely incorporated and smooth.
04 - Taste the mixture and adjust sweetness by adding more honey or maple syrup as needed.
05 - Pour the liquid mixture into silicone jelly molds or a parchment-lined, lightly oiled square baking dish.
06 - Arrange sliced fresh berries or scatter citrus zest into each mold or over the surface of the baking dish if desired.
07 - Refrigerate for at least 2 hours or until the jellies are fully set and firm to the touch.
08 - Carefully remove the jellies from the silicone molds. If using a baking dish, cut into even squares with a sharp knife. Serve chilled.