Toss the tomatoes with the oil and half of the salt and pepper.
Add the tomatoes to a baking sheet and bake for 30 minutes.
Add the butter to a frying pan and bring the heat to medium.
Add the onion and garlic and cook for 10 minutes.
Cook and drain the pasta per package instructions, reserving ½ cup of the pasta water.
When the tomatoes are done, add them to a blender with the cooked onions and garlic, along with the Mexican oregano, chipotle peppers, remaining salt, remaining pepper, pasta water, and cream.
Blend until smooth.
Combine the pasta and the sauce, top with cilantro, and serve.