In a large bowl, sift together the flour, baking powder, salt, and sugar. Make a well in the middle and pour in the milk, egg, butter, and vanilla extract. Break up the egg first with a fork and mix the wet ingredients, and then begin to combine the flour, working from the outside of the bowl in, until just combined and mostly smooth.
Cook the pancakes:
Place the Nutella in a microwave-safe bowl and heat it up, in 30-second increments, until it's melted, gooey, and spreads easily. Place it close to the pan. You might need to reheat it after a few batches as it cools.
Heat a large non-stick pan over medium heat and once hot, grease it. Immediately, pour about 2 tablespoons of batter onto the greased pan. I use a ¼cup measuring scoop and fill it halfway. Then, spoon 1 tablespoon of melted nutella over the batter, keeping it mostly in the center. Pour another 2 tablespoons of batter over the Nutella and base. I do this process (batter/Nutella/batter), one pancake at a time, but cook 3 pancakes in my pan in the same batch.
Cook the first side for 2 minutes, flip the pancakes over using a spatula, and cook the second side for 2 more minutes. Remove from the pan and repeat the process with the remaining batter.
Serve:
Plate a few pancakes on a plate and top with banana slices, strawberry slices, or your favorite toppings.