Add your pureed tomatoes. Stir to combine. Let the sauce simmer uncovered over low heat for 20 minutes. The sauce will reduce, and the bacon fat will emulsify with the tomatoes as it cooks.
After 20 minutes, check the seasoning. You may not need to add salt depending on how salty your bacon was. I recommend adding some additional black pepper at this stage as well.
Cook your pasta until it’s al dente, then toss it with the sauce and cook for another 2-3 minutes. Add in some pasta water if you need to thin out the sauce.