Pancetta can be substituted for the bacon. Any short tubular pasta is well suited to this sauce. If your tomatoes are tart, you may need to add up to 1/2 teaspoon sugar. From a back issue of Cooks Illustrated.
Cook bacon in 10-inch skillet over medium heat, stirring occasionally, until crisp, 8 to 10 minutes. Using slotted spoon, transfer bacon to paper-towel-lined plate. Pour off bacon fat from pan and discard.
Return skillet to medium-high heat. Add oil, swirl to coat pan, and add garlic, rosemary, and pepper flakes. Cook, stirring constantly, until garlic is fragrant but not browned, about 30 seconds.
Stir in tomatoes and cook until tomato pieces lose their shape to form chunky sauce, about 10 minutes.
Stir in parsley, salt, pepper, and sugar to taste.
Toss sauce with pasta and serve, sprinkling Parmesan and reserved bacon over individual bowls.