Place potatoes in a large pot and cover with cold water by 1 inch. Add salt. Bring to a boil and cook 15–20 minutes until fork tender but not falling apart. Drain well.
Transfer potatoes to a sheet pan and let sit 10–15 minutes uncovered to dry. This helps them crisp instead of steam.
Preheat oven to 425°F. Line a baking sheet with parchment paper. Brush with 1 tbsp olive oil. Sprinkle half of the Parmesan directly onto the parchment in small piles where each potato will sit.
Place potatoes on top of Parmesan piles. Use the bottom of a glass to press each potato to ¼–½ inch thickness.
Mix remaining olive oil, grated garlic, pepper, garlic powder, and seasoning in a small bowl. Brush over potatoes. Sprinkle remaining Parmesan on top.
Bake 25–30 minutes until golden brown and crispy around the edges.
Broil 2–4 minutes until deeply golden and crispy. Watch closely to prevent burning.
Brush lightly with melted butter if using. Sprinkle with parsley, lemon zest, and additional Parmesan. Serve immediately.
