Heat oven to 350°F. Grease a 9-inch round pan or small skillet.
Cook bacon until crisp, then drain and chop. Set aside.
Stir 5 tbsp melted butter with ranch seasoning and minced garlic in a large bowl. Reserve 1 tbsp butter for brushing.
Add biscuit pieces, cheddar, half the bacon, and most green onions to the bowl. Toss to coat evenly.
Pile mixture into the pan. Scatter remaining bacon and a little extra cheese on top if you like.
Bake 22–28 minutes, until golden and the center is cooked through.
Brush hot rolls with reserved butter. Sprinkle with parsley, remaining green onions, and Parmesan.
Cool 5 minutes, then serve warm and pull apart at the table.