Prep the potatoes: Peel and grate the potatoes on the large holes of a box grater. If using fresh onion, grate it now.
Remove excess moisture: Place the grated potatoes in a clean kitchen towel or cheesecloth and squeeze out as much liquid as possible.
This step is key for crisp hash browns.
Season and bind: In a large bowl, mix the potatoes with onion or onion powder, garlic powder, salt, pepper, and cornstarch. Drizzle in 1 tablespoon of oil and toss to coat evenly.
Preheat the air fryer: Set it to 380°F (193°C) for 4–5 minutes. Lightly spray the basket with oil to prevent sticking.
Shape the hearts: Place a metal heart-shaped cookie cutter on a piece of parchment or a plate.
Pack a thin, even layer (about 1/3 inch thick) of the potato mixture into the cutter. Press firmly, then lift the cutter. Repeat until you’ve used all the mixture.
If you have silicone heart molds that are air-fryer safe, you can press the mixture directly into them.
Load the basket: Arrange the heart-shaped patties in a single layer in the air fryer. Don’t crowd them. Lightly mist the tops with oil spray for extra crisping.
Air fry: Cook at 380°F (193°C) for 10 minutes.
Carefully flip with a thin spatula, spray again, and cook 6–9 more minutes, or until golden brown and crisp on both sides.
Finish and serve: Sprinkle with a pinch of salt while hot. Garnish with chopped chives or parsley if you like. Serve with ketchup, sriracha, or your favorite dip.