Step 1

For the dough: Fill a small bowl with hot tap water. Let the water sit in the bowl for 2 minutes to warm the bowl, then dump it out. In the warmed bowl, combine the yeast, sugar, 1 tablespoon of the flour and 1/4 cup warm water (105 to 115 degrees F). Let stand about 5 minutes. (The mixture will be creamy and slightly bubbly; if it isn't, start over with new yeast.)

Step 2

In a large bowl, mix together the kosher salt and remaining 2 1/2 cups flour. Make a well in the center and stir in the yeast mixture, olive oil and 3/4 cup warm water (105 to 115 degrees F) with a wooden spoon. Mix until the dough starts to come away from the sides of the bowl (it will be sticky). If the dough looks dry, add an additional 2 tablespoons warm water. Turn the dough out onto a lightly floured surface; knead with floured hands until soft and elastic, about 8 minutes. Form into a ball. (If using a stand mixer, mix on medium speed until soft and elastic, 4 to 7 minutes.) Brush another large bowl with olive oil. Add the dough and roll to coat with the oil. Tightly cover with plastic wrap and let rise in a warm place until doubled in size, 1 to 1 1/2 hours.

Step 3

Stretch the dough into the prepared baking dish. Cover with plastic wrap and let rise 30 minutes.

Step 4

Preheat the oven to 425 degrees F. Spray a 9-by-13-inch baking dish with nonstick cooking spray.

Step 5

For the topping: Use your fingertips to dimple the dough. Brush with the oil, top with the sun-dried tomatoes and rosemary and sprinkle with flaky sea salt.

Step 6

Bake until golden brown, about 25 minutes. Remove from the baking dish and allow to cool slightly before slicing into squares. Finish with a drizzle of olive oil and more flaky sea salt.