Cut off about 1/2 inch from the stem end of 1 large sweet onion. Peel and discard the outer skin. Place the onion cut-side down on the cutting board. Starting about 1/2 inch from the root, make a downward cut to the bottom of the onion. Repeat to make 3 more evenly-spaced cuts around the onion. Make 3 additional cuts between each section until you have 16 evenly spaced cuts.

Flip the onion over and use your fingers to gently pull back and separate the onion sections to separate the petals.

Place 1 cup all-purpose flour, 1 tablespoon paprika, 2 teaspoons kosher salt, 1/2 teaspoon garlic powder, 1/2 teaspoon ground cumin, and 1/4 teaspoon black pepper in a large, wide bowl, and whisk to combine. Place 2 large eggs and 1/2 cup milk in a medium bowl and whisk to combine.

Heat an air fryer to 375ºF. Meanwhile, coat the onion.

Transfer the flour mixture to a rimmed baking sheet and place the onion on top. Use your hands or a spoon to sprinkle the flour mixture over the onion, separating the petals as needed, so that the onion is well-coated all over. Shake off any excess flour if needed, then pour the remaining flour mixture back into the bowl.

Dip the onion in the egg mixture, moving the petals as needed so that it’s coated all over. Allow any excess to drip off. Return the onion to the baking sheet. Working your way around the onion, use your hands or a spoon to sprinkle the remaining flour mixture all over the onion and in between each petal, so that the onion is well-coated all over. Shake off any excess to avoid clumping.

Generously coat the onion all over, including in between the petals, with cooking spray. Lightly coat the air fryer basket with cooking spray. Use a thin metal spatula to place the onion in the basket. Air fry until crispy and golden brown all over, 30 to 35 minutes. Meanwhile, make the dipping sauce.

Place 2 tablespoons mayonnaise, 2 tablespoons sour cream, 1 tablespoon ketchup, 1 teaspoon Worcestershire sauce, 1/2 teaspoon paprika, 1/2 teaspoon garlic powder, 1/2 teaspoon kosher salt, and 1/8 teaspoon cayenne pepper in a small bowl, and stir to combine.

Remove the blooming onion from basket and serve immediately with the dipping sauce.