Cut each piece of string cheese in half widthwise. Pat pieces dry with paper towel.

Set out 3 small bowls side by side with the following ingredients. FIRST BOWL: Place flour and 1 tsp. of salt in bowl; stir together until combined. SECOND BOWL: Add eggs; beat with a whisk or fork until combined. THIRD BOWL: Stir seasoned breadcrumbs and 1 tsp. of salt together until combined.

Place one cheese piece in flour mixture; turn until covered on all sides. Put flour-covered cheese in the egg mixture; use a fork to turn it until all sides are covered with egg. Let excess egg drip back down into the bowl. Lay floured, egg-coated cheese in the breadcrumbs; roll until well-coated on all sides. IMPORTANT: Repeat this process again on the same piece of coated cheese! Dip it back in the flour, back in the egg, then give it a final roll in the breadcrumbs! **Finish all remaining cheese pieces the same way (coating each piece 2 times)

Lay each piece with a space in between each one (in a single layer) on a parchment paper-lined baking sheet. You should have 12 mozzarella bites that have each been "covered" two times. Place them in the freezer for 2 hours. This will "flash-freeze them. Don't skip this step!

To Cook: Preheat air fryer to 400°F. Spritz each piece lightly (on top) with cooking spray, olive oil or vegetable oil. Lay frozen mozzarella bites (do not thaw) in a single layer, spritzed side UP in the basket. Cook for 3 minutes, then turn each piece over. Lightly spritz top side with oil or cooking spray; continue cooking for about 3 more minutes (approx. 6 minutes total time). When done, mozzarella bites should be heated through and crispy, golden brown on the outside.

Transfer mozzarella bites to a serving plate with a dish of warm marinara sauce on the side, for dipping! TIP: Let mozzarella bites cool slightly before serving because the cheese inside is very hot when they first come out of the air fryer! Enjoy.