In a large bowl, add the flour, sugar, yeast and salt. Whisk to combine. Add the water and sourdough starter and mix with a rubber spatula or wooden spoon until the ingredients form a shaggy, sticky ball and no dry streaks remain.
Cover the bowl and let the dough rise until doubled, about 1 to 1 1/2 hours.
Place an oven rack in the center position. Preheat the oven to 425 degrees F.
Generously grease a 9-inch pie plate or 8 1/2-by-4 1/2-inch loaf pan with cooking spray or butter. (See note for other pan sizes/options.)
Scrape the dough away from the sides of the bowl with a rubber spatula, forming a rough ball in the center of the bowl. Lightly grease your hands with cooking spray or oil and place (or just kind of plop!) the dough in the prepared pan. The loaf will not be completely smooth and may look a bit rough in shape, that's ok! You can try to form the dough into a rough ball shape, tucking the edges under, but if it's too sticky, just get it in the pan. :)
Let the dough rest, uncovered, for 15-20 minutes until slightly puffy.
Bake for 15 minutes. Reduce the heat to 375 degrees F and continue to bake for 25-30 minutes until golden. Let the bread cool completely before slicing (see note).
Salt: I use table salt for this recipe. If using coarse, kosher salt, increase the salt to 2 to 2 1/2 teaspoons.Yeast: I have not tried this recipe with active dry yeast, but it should work - dissolve 1 tablespoon active dry yeast in 1/4 cup warm water until foamy and bubbling and decrease the water in the recipe by 1/4 cup - use the yeast mixture in the recipe when adding the rest of the water. Baking Pans: I prefer baking the dough in one loaf. However, the dough can be split into two pieces and baked in smaller bowls or pans (about 1 quart in size). Many people bake this dough in greased pyrex bowls, but I prefer pie plates or loaf pans. Sourdough Starter: I have not tried this recipe using 100% sourdough starter and omitting the yeast, because recipes like that need much longer rising times (often overnight), and I prefer this recipe to be quicker and easier. If using fed sourdough starter, you can probably get away with reducing the yeast to 1 teaspoon.Warm Bread: warm, homemade bread is hard to resist...and I'm not going to tell you NOT to slice into this loaf warm; however, the bread will be softer and fluffier if it cools completely.