Preheat oven to 425 degrees F.
Pour beans into casserole dish and place in oven.
In a small nonstick skillet, cook bacon over medium high heat 2 to 3 minutes. Add onions and cook 3 minutes longer. Slide the beans out of the oven. Scatter the onions and bacon around the beans. Sprinkle the brown sugar and black pepper over the onions.
Bake beans with toppings 10 minutes longer. Garnish the beans with parsley and serve.