Place a strainer over a medium bowl. Pour the tomatoes into the strainer. Add a little salt to the top of the tomatoes. Let sit for 20 minutes until most of the juices have been removed. Straining the juices out of the San Marzano canned tomatoes will make the pizza sauce nice and thick.
Place the tomatoes in a medium bowl. Use a potato masher or pastry blender to break up the tomatoes a little before cooking them.
In a medium frying pan over low- medium heat, place olive oil, garlic and oregano and cook until fragrant. It should take a couple of minutes to cook, then add the red pepper flakes at the end.
Add your strained San Marzano tomatoes to the frying pan. Gently mash them to make them a little smaller. Mix the infused oil into the tomatoes to create an herbed pizza sauce.
Add sugar, salt, and pepper to the pizza sauce.
Cook the pizza sauce for 30 minutes over low heat to let it simmer. Stir the San Marzano pizza sauce every couple of minutes.
Add fresh cut strips of basil to the pizza sauce and cook for another 5-10 minutes.
San Marzano pizza sauce is ready to use. Store in the refrigerator for up to 2 days. Store in the freezer in an airtight container for up to 1 month.