Take a roasting dish and lay the tomatoes out with the garlic. Drizzle with olive oil and season with salt and pepper. Place in the oven and roast for 15 to 20 minutes until the tomatoes have burst and juices are slightly caramelized.
Remove from the oven and place in a blender with all the pan juices. Add the red wine vinegar, 1/4 cup olive oil, sugar, parsley, and salt and pepper. Pulse until well combined. Set aside to cool in the refrigerator while you prepare the croutons.
Take a sheet tray and lay out thin slices of the baguette. Drizzle with olive oil and season with salt and pepper. Place in the hot oven and bake until golden brown and crispy. The croutons will take 5 to 7 minutes. Remove from oven and while still warm, smear each piece with some goat cheese. Set aside.
Take a platter and layer with goat cheese croutons. Top with mounds of feathery watercress and drizzle over the roasted tomato dressing.