Slice the onion into 1/4 inch slices, then separate into rings and set them aside.

In a gallon size zip lock bag, add the flour, salt, and baking powder, zip closed and shake to mix. Add some onion rings, zip closed and shake to coat the rings, remove and set the coated rings aside, repeat with the remaining onion rings.

Once all the rings are coated with flour, add the egg and milk to the zip lock bag, close and squish that up with your fingers. Add some rings, lock the bag and squish around to coat, remove to a wire rack over foil to drip. Repeat for the remaining rings.

While waiting for the rings to drip, go ahead and heat a large deep pan with oil or a deep fryer with oil, heat to 180 C (350 F), and add the bread crumbs to a shallow bowl.

While the oil is heating, place a few rings on the breadcrumbs and coat well, tap off excess, and set aside. Repeat with the remaining rings.

When the oil is hot, add a few rings at a time and fry for 2 to 3 minutes or until golden brown, remove to paper towels to drain and continue with the rest of the rings. Rings just went in during this photo.

Serve and enjoy.