Pre heat oven to 425 degrees. Coat a baking sheet with cooking spray and set aside.Cut peppers in half, lengthwise, and remove seeds. Be sure to use gloves when handling the inside of the pepper. Set aside.In a medium bowl combine cream cheese, sharp cheddar cheese, onion, garlic powder, and red pepper flakes if you like it extra spicy. Use a fork to mix it all together.Spoon the mixture by teaspoon fulls into the hallowed out peppers, and set aside. Once all of them are filled dip the top of the pepper (the side with the cheese mixture) into the lightly beaten egg. Then dip that side into the panko bread crumbs. Set cheese side up, onto the greased baking sheet.Lightly spray with the cooking spray and bake for 10-12 minutes or until the cheese starts to bubble. Some cheese may over-flow, but that’s ok. Turn on the top broiler for 1 minute just to brown the tops. Remove from the oven and serve immediately.Enjoy!