In a large bowl mix salt and flour and set aside.
Add water to a medium bowl, stir in sugar until dissolved and add yeast, let the mixture sit for 5-7 minutes for the yeast to bloom. The water should be tap warm, not hot.
Give the yeast mixture a stir and add it to the flour mixture, knead by hand or using a mixer. The dough will be a little sticky, but it should come off the walls of the bowl. If its still very, very sticky add ½ cup of flour. Knead until all flour is well combined, about 7-10 minutes. Cover the dough with a dry, clean kitchen towel, put it in a warm place and let it rise for 1-2 hours.
To speed this process, I usually turn the oven to 300F and place the bowl on top of the stove or close to the stove, since its warmer.
Once the dough tripled in size, sprinkle some flour on a flat surface and knead it for 1 minutes. Let it rest on the working surface for 10-15 minutes and using a rolling pin dusted with flour roll it into a circle or oval shape. The dough must be ½ inch thick.
Spray a loaf pan with baking spray and set aside.
Top the dough disc with the Sun Dried Tomato Pesto, spread 2 inches from the sides, followed by slices of cheese. Roll the dough into a loaf and transfer to the loaf pan.
Let it rest for another hour or 1½ hours. The loaf will double in size.
Preheat oven to 350F.
Using a kitchen brush, spread the melted butter on top of the loaf and bake for 50 - 55 minutes, until a toothpick inserted in the middle of the bread comes out clean.
Optional: Top with the melted mozzarella cheese and broil for 1-2 minutes, until cheese is golden brown and bubbly. Watch it closely not to burn the cheese.
Remove bread from oven and let it cool in the pan for one hour.
Remove from pan, slice and enjoy.