1. Preheat oven to 450°. (For a crispy crust, preheat a pizza stone on the lowest rack in the oven.)
2. Heat 2 tablespoons oil in a skillet over medium-high heat. Add leek and garlic; sauté 5 minutes or until tender. Stir in salt and pepper. Add spinach, in batches; cook 2 minutes or just until wilted.
3. Roll dough to 1/4-inch thickness on a lightly floured baking sheet or pizza peel. Brush edges of crust with remaining 1 tablespoon olive oil. Spread spinach mixture to edges of crust; top with cheeses and pine nuts, if desired.
4. If desired, transfer pizza to pizza stone dusted with cornmeal or semolina flour; bake 10 to 12 minutes or until cheese is hot and bubbly.