1 pt. grape tomatoes, halved lengthwise
1 1/4 teaspoon salt
3/4 teaspoon pepper
1 lb. shell pasta, or shaped pasta of your choice
1 1/4 cups mascarpone cheese
1 cup Parmesan cheese
1/4 cup minced chives
Preheat oven to 400˚ F. Butter a 13x9-inch baking dish. Arrange tomatoes in pan and sprinkle with salt and pepper. Roast for 15 minutes.
Cook pasta in a large pot of boiling salted water until al dente. Reserve 1 1/2 cups pasta cooking water and drain well. Transfer pasta to a large bowl. Add mascarpone and stir until cheese melts. Add reserved cooking water, tomatoes, 1/2 cup Parmesan cheese, and salt and pepper to taste.
Spoon pasta mixture into dish and sprinkle with remaining Parmesan cheese. Bake 18 to 20 minutes. Garnish with chives.