Heat 2 tbsp olive oil in a large saucepan over medium heat. Add diced 1 medium yellow onion and a pinch of salt. Cook, stirring occasionally, for 6–8 minutes until soft and translucent. Do not brown.
Add minced 5 cloves garlic and cook for 60–90 seconds until fragrant. Watch closely—burning garlic will make the sauce bitter.
Stir in 6 oz tomato paste and cook for 1–2 minutes, stirring constantly.
Pour in 28 oz crushed tomatoes 15 oz tomato sauce and ½ cup chicken broth. Stir until everything is smooth and well combined.
Add 2 tsp granulated sugar, 1½ tsp dried basil, 1 tsp dried oregano p½ tsp dried parsley, ½ tsp garlic powder ½ tsp onion powder, 1 bay leaf 1 tsp kosher salt, and ¼ tsp black pepper. Mix well to distribute flavors evenly.
Bring to a gentle boil, then lower the heat. Cover slightly and simmer for 30–35 minutes, stirring every 10 minutes.
Remove the bay leaf and stir in 1 tsp red wine vinegar. Taste and adjust seasoning. Blend briefly if you prefer a smoother sauce. Add 1 tsp red pepper flakes .
Toss with spaghetti, use as a dipping sauce, or let cool completely for storage.