Cast Iron Pandesal Pull Apart Bread

Name: Cast Iron Pandesal Pull-Apart Bread
Ingredients: 1 cup whole milk; 6 cups bread flour, divided, plus more as needed; 1/2 cup plus 1/2 teaspoon granulated sugar, divided; 1/2 cup water; 1 (1/4-ounce) packet active dry yeast (2 1/4 teaspoons); 4 tablespoons (1/2 stick) melted unsalted butter; 1/4 cup canola oil, plus more as needed; 2 large eggs; 2 teaspoons kosher salt; 1/2 cup fine, dry breadcrumbs