01 - Place the strawberries, blueberries, raspberries, and blackberries in a large mixing bowl.
02 - In a small bowl, whisk together honey or maple syrup, lemon zest, and lemon juice until blended.
03 - Pour the citrus-sweetener mixture over the berries.
04 - Gently toss the berries with the dressing until they are evenly coated.
05 - Sprinkle chopped mint leaves over the berries if desired.
06 - Serve immediately or refrigerate up to 2 hours before serving.