Drop the pasta into a pot of generously salted boiling water. Cook till about 1 minute under al dente. Drain the pasta in a colander and run under cold water to stop the cooking.
In a large bowl toss together the cooked pasta, pancetta, romaine and tomatoes until well combined.
To make the dressing:
In a small bowl whisk together the mayonnaise, vinegar, heavy cream, salt, sugar and black pepper until smooth.