Preheat your oven to 375°F (190°C) and prepare a large baking sheet by lining it with parchment paper.

In a mixing bowl, combine the shredded mozzarella, cheddar, and grated Parmesan cheese until thoroughly mixed.

Season the cheese mixture by adding Italian seasoning and garlic powder. Incorporate red pepper flakes if desired.

Halve any large slices of pepperoni to make them bite-sized.

Arrange the halved pepperoni slices onto the lined baking sheet in a single layer.

Spoon the cheese mixture generously over each slice of pepperoni.

Bake for 8-10 minutes until the cheese melts and is golden.

Allow the crisps to cool on the baking sheet for a few minutes before transferring to a wire rack.

Transfer to a serving dish and garnish with freshly chopped parsley if desired.

Store leftovers in an airtight container at room temperature.