Toast the caraway seeds in a sauté pan over medium heat for 2 minutes or until fragrant and lightly browned. Crush the seeds with a mortar and pestle, or on a cutting board with the bottom of a heavy skillet.
Toss cabbages, scallions, cucumber, carrot, bell pepper, cilantro and dill in a large bowl. Whisk vinegar, syrup, salt and pepper in a medium bowl; whisking constantly, slowly drizzle in oil until emulsified.
Add caraway seeds and dressing to vegetable mixture and toss until well combined. Refrigerate at least 30 minutes before serving.