Preheat your oven to 400°F (200°C). Coat the bottom of a baking sheet with avocado or olive oil.
Rinse and dry the mushrooms, then set them aside.
Using a blender or food processor, grind raw sunflower seeds until they reach a fine, powdered texture.
In a zippered storage bag, combine the ground sunflower seeds, almond flour, garlic powder, sea salt, paprika, parsley, and optional parmesan cheese. Close the bag and shake to mix the ingredients thoroughly.
In a small bowl, beat the egg (or 2 regular eggs) and, if using, mix in the melted butter.
Dip each mushroom into the egg mixture, then place it into the zippered bag with the almond flour mixture. Close the bag and shake until the mushroom is evenly coated with the breading.
Transfer the coated mushrooms to the prepared baking sheet.
Bake for 12-14 minutes, turning the mushrooms halfway through baking.
After baking, switch the oven to broil on low for an additional 1-2 minutes to crisp up the coating. Be sure to check after 1 minute to avoid burning.
Remove from the oven, allow to cool slightly, and serve warm.