Preheat oven to 200C/400F
Place flour and baking powder in large bowl.
Whisk the eggs and milk together.
Add the melted butter to the milk and egg mixture and stir.
Place onion, cheddar, bacon, corn and parsley in the bowl with the flour and baking powder.
Add the eggs, milk and butter.
Stir until well combined and season with salt and pepper.
Grease a muffin tin with melted butter or coconut oil using a pastry brush.
Use a tablespoon to generously dollop the muffin mixture into the tin. Avoid over filling because they will rise.
Place in oven, bake for 20-30 minutes, or until muffins are golden brown and sound 'hollow' when tapped.