Use a mandoline, knife, or food processor to cut the potatoes into fries.
Place the potatoes in a dutch oven filled with cold water.
Bring the water to a boil and add the salt and baking soda.
Return to a boil and cook for 3 minutes, until the potatoes are just cooked through but not mushy.
Drain and place on a baking sheet. Dry with paper towels.
Chill for an hour, or up to overnight.
Preheat the air fryer to 375° F.
Spray the potatoes well with oil and arrange in your air fryer in a single layer, cooking in batches if necessary.
Cook for 12 to 15 minutes, until golden brown.
Place the fries in a 200° F oven while the remaining fries cook.
Meanwhile, melt the butter and then add the garlic and rosemary.
Drizzle the butter over the warm fries and gently toss to coat.
Top with parmesan, parsley, and salt, and serve warm.