Diner Fried Onion Rings

You've been to a dinner where they serve
the best darn fried onion rings ever.
Here's the recipe, don't tell anybody.

Ingredients:
1 large onion, cut into 1/4 inch slices
1 1/4 cups all-purpose flour
1 teaspoon baking powder
1 teaspoon salt
1 egg
1 cup milk, or as needed
3/4 cup dry bread crumbs
seasoned salt to taste
1 quart oil for frying, or as needed

Directions:
Heat oil in a deep fryer to 365 degrees.
Separate the onion slices into rings,
In a small bowl, stir together the flour,
baking powder and salt.
Dip the onion slices into the flour mixture
until they are all coated.
Whisk the egg and milk into the flour mixture.
Dip the floured rings into the batter to coat,
Spread the bread crumbs out on a plate or shallow dish.
Place rings one at a time into the crumbs,
Repeat with remaining rings.
Deep fry the rings a few at a time
until golden brown.
Remove to paper towels to drain.
Season wit salt, and serve.