Preheat the oven to 425F. Line a large baking sheet with a silicone mat or parchment paper and set aside. Separate the onion slices into rings. Transfer to a bowl and set aside.
In a shallow bowl, combine the oat flour, chickpea flour, Almond Milk, and vinegar. Stir to blend well.
In a separate shallow bowl, combine the cornmeal, bread crumbs, nutritional yeast, Savory Spice Blend, and paprika. Mix well.
In a row, line up the bowls of onion rings, batter, breading mixture, and the prepared baking sheet. Dip an onion ring into the batter, coating it all over. Transfer the onion ring to the breading, tossing to coat. Use a clean, dry hand to sprinkle the breading onto the onion as needed. Place the coated onion ring on the baking sheet and repeat with the remaining ingredients, arranging the rings in a single layer. Use a second sheet if needed. You should have enough batter and breading for about 20 onion rings.
Bake for 10 minutes, then remove from oven and carefully turn rings over. Bake for about 10 minutes longer, or until crisp and nicely browned. Serve hot.