Asparagus retains its character even when paired with flavorful ingredients, like the bacon used to give depth to this simple pasta dish.
Snap off and discard the tough ends of the asparagus. Cut the asparagus into 1-inch pieces on the bias; set aside. Bring a large pot of salted water to a boil.
Cook the bacon in a skillet over medium heat until bacon is crisp and all the fat has been rendered, 15 to 20 minutes. Remove the bacon from pan, and drain on paper towels. Crumble the cooked bacon, and set aside. Remove skillet from heat.
Add the pasta to the boiling water, and cook until al dente, 5 to 7 minutes. Drain pasta in a colander; set aside.
Meanwhile, discard all but 1/4 cup bacon fat, and return the skillet to medium heat. Add the asparagus and the red-pepper flakes to the skillet. Cook until the asparagus is lightly browned. Drain the pasta, and add to skillet with the crumbled bacon, and the marjoram; season with salt. Toss together until combined and heated through. Remove the skillet from the heat.
Add the mozzarella, and toss to combine. Divide the pasta among six plates. Garnish each serving with a grind of black pepper, and serve immediately.