Prepare Pancake Batter: In a large bowl, whisk together the flour, sugar, baking powder, and salt. In a separate medium bowl, whisk the egg and milk. Pour the wet ingredients into the dry ingredients and mix until just combined—do not overmix; a few lumps are okay. Stir in the melted butter.
Cook the Pancakes: Heat a lightly oiled griddle or non-stick pan over medium heat. Drop the batter by the tablespoon to create small, 2-3 inch silver-dollar pancakes. Cook for 1-2 minutes per side, until golden brown. You should have about 12-14 small pancakes. Let them cool completely.
Assemble and Freeze: Spread a generous tablespoon of Nutella on one pancake and top with another to create a sandwich. Repeat for all pancakes. Place the assembled sandwiches on a parchment-lined baking sheet and freeze for at least 15-20 minutes. This step is crucial to prevent the Nutella from melting out during frying.
Set Up Breading Station: While the sandwiches are freezing, prepare your breading station. Place the flour in a shallow dish. In a second shallow dish, whisk together the 2 beaten eggs and 1/4 cup of milk. In a third shallow dish, place the breadcrumbs.
Coat the Sandwiches: Remove the chilled sandwiches from the freezer. Dredge each sandwich first in the flour, shaking off any excess. Then, dip it completely in the egg wash. Finally, coat it evenly in the breadcrumbs, pressing gently to adhere.
Fry to Golden Perfection: In a heavy-bottomed pot or deep skillet, heat about 2 inches of oil to 350°F (175°C). Carefully place 2-3 coated sandwiches into the hot oil. Fry for about 1-2 minutes per side, until golden brown and crispy. Do not overcrowd the pan.
Drain and Serve: Using a slotted spoon, remove the fried sandwiches and place them on a wire rack to drain any excess oil. Serve immediately, dusted generously with powdered sugar. Enjoy the warm, gooey center!