1. Heat oven with pizza stone inside to 500 degrees F at least 1 hour prior to baking.
2. Dough. In a small bowl, stir together 1 1/2 cups warm water (between 100 and 110 degrees F), yeast and sugar. Set aside for 10 minutes.
3. Combine flour and salt in a large bowl. Make a well in the center and pour yeast mixture and oil into it. Slowly stir yeast mixture into flour (from the inside out). Finish bringing together dough by hand in bowl until most of flour is absorbed (if it feels too sticky, add more flour). Place dough on a clean surface and knead until it slowly springs back when pressed, about 2 to 3 minutes. Divide dough in half. Lightly coat two bowls with olive oil and place one piece of dough into each. Cover and set aside in a warm place to rise for 45 minutes.
4. Meanwhile, make topping. Break tough ends off asparagus and cut each stalk into thirds. Place asparagus in a bowl and toss in oil, 1/4 teaspoon of the salt and 1/8 teaspoon of the pepper. In another bowl, mix together ricotta, garlic and remaining 1/8 teaspoon each of the salt and pepper.
5. Punch down dough in both bowls. Wrap one ball tightly in plastic wrap, place in a resealable bag and freeze for later use. Form other ball into 12- to 14-inch circle. Sprinkle cornmeal or semolina flour on pizza peel and place dough on top. Scatter asparagus over dough. Dollop ricotta mixture on top. Transfer from peel to stone, and bake at 500 degrees F for 12 minutes or until crust is browned and cooked through. (If you don't have a peel, use the back of a pizza pan to transfer to the stone. No stone? Bake pizza on pan at 500 degrees F for 14 minutes or until browned.) Zest lemon on top of pizza and drizzle with more olive oil, if desired.