Pour boiling water into a mixing bowl and add berry gelatin powder.
Stir until the gelatin is completely dissolved.
Add cold water and mix well.
Add fresh strawberries, blueberries, raspberries, and blackberries.
Pour the mixture into a serving dish or individual cups.
Refrigerate for 3–4 hours or until fully set.
Serve chilled and garnish with fresh berries and whipped cream if desired.