Preheat the oven to 400ºF. Coat a 9x13 baking dish with olive oil or cooking spray.

Place the spinach in an even layer in the baking dish. Add about half the grated cheese, then crack the eggs over the top, spacing them out evenly. Sprinkle with salt and pepper and drizzle the heavy cream over the top. Top with the remaining cheese. Place in the oven for 15-25 minutes, checking every few minutes towards the end for desired doneness.

While the eggs are baking, melt the butter in a small saucepan over medium heat. As it begins to bubble, whisk constantly until little brown bits begin to form on the bottom of the pan. Remove from the heat and whisk for an additional 30 seconds, then let stand for 2 minutes. Whisk in the minced garlic, then stir in the panko until well coated.

Once the eggs are done, remove them from the oven and sprinkle with breadcrumbs and chopped parsley. Scoop one egg onto each toasted bun and serve.