Steam spinach until tender and set aside to cool in a colander placed over a bowl to catch any excess moisture. (Steaming preserves vitamins, so since it cooks quickly, be careful to avoid overcooking the spinach, which will negate that advantage.)
Cook bacon until crispy in a saute pan and remove to paper toweling to drain and cool. Pour most of the fat out of the pan and add the cream to the same pan over low heat, allowing to reduce by about one-third.
Whisk the Parmesan into the reduced cream, and season with pepper. Since the cheese will add saltiness, add salt only if needed. Fold the well-drained spinach and bacon into the sauce. Transfer to a serving dish.