Begin by thoroughly washing the mushrooms under running water to remove any dirt. Pat them dry with a clean kitchen towel or paper towel. If needed, trim the stems to create a uniform appearance.

In a medium-sized bowl, mix together the flour, paprika, garlic powder, onion powder, baking powder, salt, and black pepper until evenly combined. In a separate bowl, whisk the buttermilk and egg together to create a smooth, cohesive mixture.

Dip each mushroom into the buttermilk mixture, ensuring it is fully coated. Lift it gently and allow any excess liquid to drip off. Roll the mushroom in the flour mixture, pressing lightly to ensure a thorough and even coating. For an extra crispy crust, repeat the dipping and coating process.

In a deep skillet or fryer, heat about 2 inches of cooking oil to 350°F (175°C). The oil should be hot enough to sizzle when a small pinch of batter is added.

Carefully add a few mushrooms to the hot oil at a time, avoiding overcrowding the pan. Fry them for 2 to 3 minutes, turning occasionally, until they develop a golden-brown and crispy exterior. Remove the mushrooms with a slotted spoon and transfer them to a plate lined with paper towels to absorb any excess oil.

Arrange the crispy fried mushrooms on a serving platter. Serve immediately while hot, accompanied by your favorite dipping sauce, such as ranch or spicy mayo. Enjoy their irresistible crunch and juicy interior.