Gather your ingredients. Bring a pot of water to a boil and prepare a bowl with cold water and plenty of ice.
Thoroughly wash your tomatoes, remove the core from the tops of the tomatoes, and use a very sharp knife to cut a shallow "x" at the bottom of each tomato.
Blanch the tomatoes in the boiling water for 20-30 seconds.
After blanching the tomatoes, immediately place them in the prepared ice bath.
When the tomatoes are cool enough to handle, transfer them to a cutting board. Using either your hands or a paring knife, peel the skins. Then, cut each tomato into quarters.
In a medium saucepan over medium heat, add oil. Once hot, add the onion and cook until soft, 3-5 minutes. Add garlic and cook for 1 minute.
Add the tomatoes and gently mash them down. Then, add oregano, basil, salt, sugar, and bay leaf. Stir well.
Reduce the heat to low, cover, and simmer for 1 hour, stirring occasionally. After the hour, remove the bay leaf and Use an immersion blender to smooth out the sauce and incorporate all of the ingredients. Serve immediately.