To a blender, add the Italian dressing, 1/2 of the raspberries, and the sugar substitute, and blend for a minute until smooth.
Line a bowl or plate with whole radicchio leaves and pile high the lettuce mix in the center. Cut a tomato into 4 wedges and place around the plate in a starburst fashion with a heart of palm stick in between each. Sprinkle with minced bell peppers. Pour raspberry vinaigrette over the salad and top with a few fresh raspberries. Serve.