Bloom the gelatin: In a small bowl, sprinkle the gelatin (or agar) over ½ cup cold water. Let it sit 5–10 minutes until fully absorbed and gelled.

Make your puree: In a blender, combine the thawed mango and dragonfruit, 1 cup water, lemon juice, and maple syrup. Blend on high until completely smooth and evenly pink-orange.

Heat and incorporate: Pour the puree into a small saucepan and warm over low heat (120–140°F), stirring gently—do not let it boil. When it's hot to the touch, whisk in the bloomed gelatin until fully dissolved and silky.

Spread into a sheet: Line a rimmed baking sheet with parchment paper. Pour in the mixture, then tilt/drag an offset spatula to spread it about ⅛ inch (3 mm) thick.

Dry out: Place in your oven at its lowest setting (150–170°F). Prop the door open slightly (a wooden spoon works great) so moisture escapes. Dry for 4–6 hours, or until the sheet is no longer tacky and peels cleanly.

Cut into straws: Let the fruit leather cool fully. Use kitchen scissors or a pizza cutter to slice into thin strips (~¼ inch wide × 4–5 inches long).

Toss in sour coating: In a small bowl, whisk the citric acid with cane sugar (if using). Lightly mist each strip with water, then toss in the coating. Shake off any excess.

Finish & store: Lay coated straws on a wire rack for 10 minutes to set. Store in an airtight container at room temperature for up to 2 weeks.