To make cheese and bacon lunchbox muffins, chop bacon and scallions, and keep aside while preparing remaining ingredients.
In a large bowl, blend and combine all the dry ingredients.
In a separate bowl, whisk together buttermilk, oil, and egg to break up the egg.
Combine dry and wet ingredients for your cheese and bacon lunchbox muffins. Gently mix, then add the bacon, cheese and onions.
Stir until everything is just combined. It's fine if there are small lumps; overmixing will result in tough muffins.
Distribute the lunchbox muffins mixture evenly among the muffin cups.
Bake until the muffins are puffed, cooked through, and golden brown, about 15-20 minutes.
Take the muffin pan out of the oven. Allow the cheese and bacon muffins to cool for 5 minutes before transferring onto a cooling rack.
Cheese and bacon lunchbox muffins are perfect to pop into kids or adults lunchboxes all week long! Store in the freezer, add to your lunchbox in the morning and they'll be thawed by lunchtime.