Cut the paneer block into 1-inch cubes. If using firm paneer, there's no need to press it. If your paneer is soft, you can wrap it in a paper towel and gently press for 10 minutes to remove excess moisture.
In a small bowl, whisk together the yogurt (or buttermilk) with half of the spices: 1 tsp kashmiri red chili powder, 1/2 tsp garlic powder, 1/2 tsp ginger powder, 1/2 tsp cumin, 1/2 tsp coriander, 1/2 tsp chaat masala, 1/2 tsp amchur, and 1/2 tsp salt.
Add the paneer cubes to the yogurt-spice mixture. Gently toss to ensure each piece is evenly coated. Cover and let it marinate for 15-20 minutes at room temperature.
Set up your breading station: Use three separate shallow bowls. In the first bowl, place the all-purpose flour (or cornstarch). In the second bowl, place the remaining yogurt marinade (it will be thick). In the third bowl, combine the panko breadcrumbs, rice flour (if using), and the remaining half of all the spices.
Take a marinated paneer cube. Dredge it in the flour, shaking off any excess. Next, dip it back into the thick yogurt marinade. Finally, roll it in the spiced breadcrumb mixture, pressing gently to ensure an even and thorough coating. Place on a plate. Repeat for all pieces.
Preheat your air fryer to 390°F (200°C) for 5 minutes. Lightly spray the air fryer basket with oil.
Arrange the coated paneer bites in the basket in a single layer, making sure they are not touching. Lightly spray the tops with cooking oil.
Air fry at 390°F (200°C) for 10-12 minutes, or until the coating is golden brown and crispy, flipping them halfway through the cooking time. No need to spray again after flipping.
Remove the crispy paneer popcorn from the air fryer. Immediately sprinkle with a little extra chaat masala for a tangy kick. Serve hot with mint chutney or your favorite dipping sauce.