Preheat a waffle iron to medium-high heat.
Cut each Frigo® Cheese Head® String Cheese stick in half lengthwise and crosswise, yielding 4 pieces per stick, 24 pieces total.
Spray both sides of the waffle iron with nonstick cooking spray and sprinkle 1/2 tablespoon of the breadcrumbs in a square shape. Repeat 3 more times so you have 4 squares.
Place 3 string cheese pieces, lined up in a square shape on top of each square of breadcrumbs. Then, sprinkle the cheese with another 1/2 tablespoon of breadcrumbs over all four squares.
Close the lid and cook until the breadcrumbs just turn golden, about 1 minute. Watch closely; if the cheese gets too soft, it will be hard to remove.
Repeat with the remaining cheese and breadcrumbs. Serve hot with the marinara for dipping.