Make the Dough: Whisk together the flour, cornmeal, salt, sugar, and yeast in a large bowl.
Add water and melted butter and mix on low speed, using a dough hook, until fully combined, 1 to 2 minutes, scraping sides and bottom of bowl occasionally. Increase speed to medium and knead until the dough is glossy and smooth and pulls away from sides of the bowl, 4 to 5 minutes. (You can easily make this by hand, mixing in the water and butter with a spatula and then kneading by hand.)
Coat a large bowl with 1 teaspoon olive oil. Using a greased spatula, transfer the dough to the bowl, turning to coat the dough in oil; cover tightly with plastic wrap. Let rise at room temperature until nearly doubled in volume, 45 to 60 minutes.
Make the Sauce: While dough rises, heat the butter in a medium saucepan over medium heat until melted. Add onion, oregano, and salt; cook, stirring occasionally until liquid has evaporated and onion is golden brown, about 5 minutes. Add garlic and cook until fragrant, about 30 seconds.
Stir in tomatoes and sugar, increase heat to high, and bring to a simmer. Lower heat to medium-low and simmer until reduced to about 2½ cups, 25 to 30 minutes. Off the heat, stir in the basil and olive oil, then season with salt and pepper.
Laminate the Dough: Turn the dough out onto dry work surface and roll into a 15×12-inch rectangle. Using an offset spatula, spread the softened butter over the surface of the dough, leaving a ½-inch border along the edges. Starting at the short end, roll the dough into a tight cylinder. With seam side down, flatten the cylinder into an 18×4-inch rectangle.
Cut the rectangle in half crosswise. Working with one half, fold into thirds like a business letter; pinch seams together to form a ball. Repeat with the remaining half. Return balls to the oiled bowl, cover tightly with plastic wrap and let rise in refrigerator until nearly doubled in volume, 40 to 50 minutes. Meanwhile, adjust oven rack to lower position and preheat oven to 425 degrees F.
Bake the Pizzas: Coat two 9-inch round cake pans with 2 tablespoons of olive oil each.
