Warm olive oil in a large skillet (12-inch) over medium heat. Add onion with a good pinch of salt. Cook 6–8 minutes, stirring, until soft and lightly golden.
Add garlic, oregano, cumin, cinnamon, and red pepper flakes. Stir 30–45 seconds until fragrant. If it looks dry, splash in a bit more oil.
Pour in tomatoes. Add sugar or balsamic if your tomatoes taste sharp. Simmer 8–10 minutes, stirring, until thickened. Taste and season with salt and pepper.
Fold in spinach by handfuls until wilted, 1–2 minutes. Stir in half the feta.
Use a spoon to make small wells. Crack an egg into each. Sprinkle with salt and pepper. Cover and cook 6–9 minutes over medium-low, until whites set and yolks stay jammy. Adjust time for firmer yolks.
Top with remaining feta and herbs. Drizzle with a little olive oil. Serve right from the pan. Boom.