If you have never roasted a tomato before, be warned...you will fall in LOVE! When you roast the tomatoes over time they build this sweet flavor, one word - divine! I normally roast more than the recipe calls for and throw them in my salads, sandwiches, or sauces during the week. Simply magnificent!
To prepare roasted tomatoes, preheat oven 275 degrees and place a rack in the center. Place tomato halves in a medium mixing bowl and toss gently with 1/3 cup olive oil, garlic, and thyme sprigs. Season with salt and pepper. Arrange tomatoes on a rimmed baking sheet in a single layer and pour juices from bowl over tomatoes. Roast in preheated oven until golden brown and slightly shriveled, about 2 hours. Check tomatoes every 20 to 30 minutes, removing any that have browned. Remove tomatoes from oven and cool to room temp. Remove thyme sprigs and discard.
Preheat broiler and arrange baguette slices on a rimmed baking sheet lined with foil. Brush tops with olive oil and sprinkle lightly with salt and pepper. Toast until golden brown on top.
To serve, remove baguette slices from oven and top with 4 or 5 cherry tomato halves, gently pressing to adhere. Drizzle each crostini with balsamic vinegar and top with basil ribbons. Serve immediately.