01 -  Preheat the oven to 400°F. Line a baking sheet with parchment paper. 
 02 -  Pierce potatoes several times with a fork and arrange directly on the oven rack. Bake for 45 to 50 minutes, or until fork-tender. Allow potatoes to cool slightly after baking. 
 03 -  While potatoes are baking, steam broccoli florets in a vegetable steamer or saucepan for 3 to 4 minutes, until just tender and bright green. Set aside. 
 04 -  Slice baked potatoes in half lengthwise. Carefully scoop out most of the flesh with a spoon, leaving a 1/4-inch thick shell. Reserve potato flesh for another use. 
 05 -  Brush both interior and exterior of potato skins with melted butter using a pastry brush. Season with garlic powder, salt, and pepper. Place skin-side up on the prepared baking sheet. 
 06 -  Bake potato skins for 10 minutes until they begin to crisp. Flip over and continue baking for 5 minutes more. 
 07 -  In a mixing bowl, combine steamed broccoli, Alfredo sauce, half the shredded mozzarella, and half the grated Parmesan. 
 08 -  Mound broccoli-Alfredo mixture evenly into each potato skin. Top with remaining mozzarella and Parmesan cheese. 
 09 -  Return filled potato skins to oven and bake for 10 to 12 minutes, until cheeses are fully melted and bubbling. 
 10 -  Sprinkle with chopped fresh parsley to garnish, if desired. Serve immediately while hot.