Preheat the oven to 350°F. Grease or line a 9x9-inch pan with parchment paper.
In a large bowl, whisk eggs, cottage cheese, and olive oil until smooth.
Fold in the flour, salt, pepper, garlic powder, and baking powder until just combined.
Gently fold in the whole spinach leaves and 1 cup shredded cheddar.
Spread mixture evenly in the pan. Sprinkle with the reserved cheddar and Parmesan.
Bake for 35–40 minutes, until golden on top and set in the center.
Cool for 20 minutes, then slice into 9 bars. Sprinkle with chives before serving, if desired.
Store leftovers in an airtight container in the refrigerator for up to 4 days, or freeze tightly wrapped bars for up to 2 months. Thaw overnight in the fridge before reheating.
