Preheat the oven to 400 degrees F. Mix the parmesan, basil and lemon zest in a bowl.
Transfer a heaping tablespoon of the cheese mixture to a silicone- or parchment-lined baking sheet and lightly pat down. (A silicone baking mat is highly recommended for this recipe.) Repeat with the remaining cheese mixture, spacing the spoonfuls about 1/2 inch apart. Bake 3 to 5 minutes, or until golden and crisp. Let cool, then use a flat spatula to remove.