Preheat the oven to 350. Line a muffin tray with paper liners.
In a food processor, add cashews and unsweetened coconut. Process on high until creamy. About 1-2 minutes. You may have to scrape down the sides a couple times.
While the machine is running, add one egg at a time. Your batter should be smooth and creamy.
Transfer to a large bowl.
Add baking soda, lemon juice, feta cheese and finely chopped spinach. Stir to mix.
Use an ice cream scoop or large spoon to transfer batter to the muffin tins, filling to 3/4 full.
Bake in the oven about 25 minutes. Muffin tops should be golden brown.