Preheat the oven to 350°F. Line baking sheets with parchment paper.
Mix together Manchego cheese with dried rosemary (optional) or chili powder (optional).
Place 1 tablespoon cheese onto prepared baking sheets, leaving 2 inches between each mound. Bake until cheese is golden brown and lacy, about 5 minutes. Watch carefully.
Allow to cool for 1 minute on baking sheet.
Remove and cool on a drying rack until crispy.