Preheat oven to 450°F.
In a large skillet, cook bacon until slightly crispy. Remove bacon and drain.
Retain bacon grease in the skillet and sauté the spinach until wilted, about 2 to 3 minutes. Drain any liquid from the spinach if necessary.
Brush some of the warm bacon grease over the pizza crust (optional), and then top with the spinach, bacon, and walnuts, followed by two-thirds of the cheddar cheese.
Reduce oven heat to 425° and bake for 8 to 10 minutes or until the crust is light brown.
Top with the blueberries and remaining cheddar cheese, and then sprinkle the parmesan cheese on top.
Bake another 1 to 2 minutes or until the parmesan cheese is melted and golden brown.
Slice and serve. Serves 6.