1. Preheat oven to 425 degrees F. Line two baking sheets with foil and spray with cooking spray, then grease each pan with vegetable oil.
2. Put half the thawed spinach in a sieve and use the back of a large spoon to press out excess liquid. Place drained spinach in a large bowl. Repeat with remaining spinach. Add grated potatoes and onion to bowl and use a fork to mix well, then add salt, pepper, parsley, sage, and chives, if using. Mix well.
3. Add eggs and mix thoroughly. Add ricotta cheese, if using, and mix well to distribute.
4. Use a soup spoon to scoop a heaping anount (about 3 Tbsp.) of potato-spinach mixture for each latke. Place scoops on prepared baking sheets and press each into a flat pancake shape with the back of a spatula. Latkes can be close together - about 1/2 inch apart - as they will not spread during cooking.
5. Bake latkes, two sheets at a time, for 15 at 425 degrees F. After 15 minutes, remove pans from oven. Spray top of each latke with olive oil cooking spray, then flip over. Return pans to oven and bake an additional 12 to 15 minutes, until latkes are brown around edges and on top. Serve warm. Latkes may be made in advance and refrigerated. Reheat at 300 degrees F until warm, about 10 minutes.
Source: Hannaford fresh Magazine, November - December 2008