Peel the small onions and trim their stems, leaving the root end intact to help them hold together. Slice off the very top and bottom to create a flat surface, then carefully make shallow cuts into the onion, creating petals that can slightly spread open. Set aside.
In a large mixing bowl, whisk together the flour, baking powder, paprika, and cayenne pepper until evenly combined. In a separate bowl, beat the eggs and milk together until smooth.
Dip each prepared onion into the wet mixture, allowing excess to drip off, then coat it thoroughly in the seasoned flour mixture, pressing gently to ensure the petals get a good coating. Repeat if you want a thicker crust.
Heat the oil in a deep fryer or large pot over medium-high heat until it reaches about 350°F (175°C). To test, drop a small piece of batter—if it bubbles and rises steadily, the oil is ready.
Carefully lower the coated onions into the hot oil, working in batches to avoid crowding. Fry for about 3-4 minutes, turning occasionally, until the onions are golden brown and crispy.
Use a slotted spoon to remove the fried onions and transfer them to a paper-lined baking sheet. Let them drain and cool slightly for a few minutes, until crispy and fragrant.
Serve the mini blooming onions warm, with your favorite dipping sauce or enjoy their crispy, caramelized sweetness on their own.
