Preheat oven to 425 degrees F. For plum tomatoes, slice the tomatoes in half lengthwise. For cherry tomatoes, leave whole.

Lay tomatoes out onto an un-greased baking sheet. Drizzle with olive oil and sprinkle garlic cloves throughout. Season with sugar and salt and toss to coat. Spread out into a single layer.

Roast in the preheated oven for 15 to 20 minutes for cherry tomatoes, and 35 to 40 minutes for plum tomatoes.