Add tomatoes to a large bowl and crush them with your hands. Remove any brown stem points if desired. Set aside. See Recipe notes for using fresh San Marzano tomatoes.
In a large deep sauce pan or dutch oven, add olive oil and butter. Heat over medium heat until butter is melted. Add garlic, stir constantly, heating until the garlic sizzles, about 30 seconds. Add the red chili flakes and stir to incorporate.
¼ cup olive oil, 1 tbsp butter, 8 cloves garlic, ¼ tsp red chili flakes
Add the tomatoes to the pan, along with the salt, basil, and oregano. Sprinkle the granulated sugar and stir to combine all the ingredients. Turn heat to medium-high and let come to a hard simmer.
2 28-oz cans whole San Marzano tomatoes, 1 tsp sea salt, 2 tbsp chopped fresh basil, 1 tsp chopped fresh oregano, 1 tsp granulated sugar
Lower heat to medium-low and simmer for 30 minutes or until the liquids have evaporated to the thickness you like. Taste and add more salt as desired.
If you want a smooth sauce, carefully blend in the pot with an immersion blender or pour into a blender and blend smooth.
Serve immediately over cooked pasta or use as a base for lasagna, pizza, or for dipping bread. If not using immediately, the sauce can be refrigerated for up to 5 days before serving, or frozen for 3 months. To use after freezing, defrost in the fridge overnight and then heat as needed.