Place a pizza stone or heavy baking sheet in the oven. Preheat the oven to 500 degrees.
Place the dough in a medium microwave-safe bowl coated with cooking spray. Cover and microwave at 50% power for 45 seconds. Let stand 5 minutes.
Combine the water and porcini in a 2 cup glass measuring cup. Microwave at high for 4 minutes or until tender. Drain. Coarsely chop the porcini.
Heat a large skillet over medium-high heat. Add oil; swirl to coat. Add the fresh mushrooms and garlic. Saute for 5 minutes. Stir in the porcini, pepper, and salt.
Roll the dough into a 12x8 inch rectangle on a floured surface. Carefully remove the pizza stone from the oven; arrange the dough on the pizza stone. Spread the pesto over the dough, leaving a 1/2 inch border. Sprinkle the cheese over the pesto; top with the mushroom mixture. Bake at 500 degrees for 13 minutes or until the crust is crisp and brown. Cut into 8 pieces.