Preheat the oven to 400 degrees. Line a baking sheet with foil or silicone liner, and lightly coat with cooking spray.
Place the tomatoes in a single layer on the prepared baking sheet. Drizzle the tomatoes with the olive oil, and sprinkle them with garlic, oregano, salt and pepper.
Roast until the tomatoes are slightly shriveled and soft, 15 to 20 minutes. Roughly chop the tomatoes and set aside.
In a small bowl, whisk together the balsamic vinegar, mustard, agave (or honey), rosemary, salt and pepper. Slowly whisk in the olive oil until combined.
Cook the pasta according to package directions. Drain and rinse with cold water. Let drain.
In a large bowl, combine the arugula, pasta, cannellini beans and roasted tomatoes.
Pour in the dressing and toss to coat the salad. Divide between plates and serve.