Preheat the oven to 350 degrees F. Lightly spray an 11 by 7-inch baking dish with nonstick cooking spray.
In a large bowl, combine the artichokes, cream cheese, mayonnaise, sour cream, 1/2 cup Parmesan cheese, 1/2 teaspoon salt, pepper and hot sauce if desired. Stir well. Spoon into the prepared baking dish. Sprinkle the remaining 1/4 cup Parmesan on top. Bake until bubbly, 25 to 30 minutes.
In a small skillet, heat the oil until hot. Add the leeks and fry, stirring constantly, until crisp, about 5 minutes. Drain on paper towels and sprinkle with salt if desired. Sprinkle over the dip before serving. Serve warm with baguette slices or assorted crackers.
Dip can be made ahead up to 24 hours, refrigerated and reheated. Sprinkle with the leeks just before serving.