fettuccine • olive oil • shallots, diced (enough for about 1 cup) • garlic, minced • dry white wine • cans cherry or baby Roma tomatoes OR 1 (28 oz) can whole San Marzano tomatoes • kosher salt • white sugar • dried oregano • jumbo lump crabmeat, picked through for shells (fresh or canned is fine) • unsalted butter, at room temperature • shredded Parmesan cheese, plus more for serving •