For the dry batter:
For the wet batter:
Heat your oven to 400 degrees. Line a baking tray with parchment paper or a silicone baking matt.
Mix together all the dry ingredients in a medium sized bowl. Mix together the wet ingredients in another bowl.
Slice the onion to make rings that are about 3/4 of an inch wide. Peel the skin from each ring and carefully separate the rings from each other.
One at a time, take each ring and dip it into the wet mix. Then drip it into the dry. Coat it well, but make sure to tap all the excess back into the bowl. Place the ring on the baking tray.
When all the rings are coated, spray the rings with olive oil spray. You want to coat them, but not get too much. Flip them over and spray the other side.
Pop them into the oven. Check them after 9 or 10 mins and flip them over. Cook for an additional 4 mins or so. They are best served right away.
Original Recipe from Cooks with Cocktails.