Tomato and Parmesan Focaccia with Caramelized Onions

INGREDIENTS

Dough:

1 cup

warm water (100° to 110°)

2 tbsp

olive oil

1 tsp

sugar

package dry yeast (about 2 1/4 teaspoons)

2 3/4 cups

all-purpose flour (about 12 1/3 ounces), divided

1/4 cup

yellow cornmeal

1 tsp

salt

Cooking spray

Topping:

1 tbsp

olive oil

4 cups

thinly sliced yellow onion

1 tsp

dried basil

1/2 tsp

salt

1/4 tsp

freshly ground black pepper

(1/8-inch-thick) slices tomato

1/3 cup

(about 1 1/2 ounces) grated fresh Parmesan cheese

1/4 cup

thinly sliced fresh basil