Preheat the oven to 350° F.
Remove the top 1/3 of the bread. Pull out some of the inside of the bread to create space for the eggs. Be conservative with the amount you pull out. You do want a thick layer of bread at the bottom. Rub with olive oil and sprinkle bagel seasoning, salt, and pepper. Bake for 5 minutes or until the bread is toasted.
Meanwhile, whisk together the eggs, milk, salt, pepper, and chili flakes. Stir in the spinach and 1/2 cup shredded cheese.
Sprinkle the bottom of the bread with the 1/4 cup cheese, then drizzle over a tablespoon or two of the pesto. Slowly pour in the eggs. Let the brad absorb the egg mixture for a few moments. Top with the remaining cheese. Bake 30 minutes, until just set in the center.
Top with bacon (recipe below!), pesto, and chili crisp. Enjoy!