In a large bowl, whisk together the flour, baking powder, sugar, and a pinch of salt until well combined.
Create a well in the center of the dry ingredients and add the egg, milk, and vanilla essence (if using). Gently whisk the wet ingredients into the dry, mixing just until the batter is smooth and free of lumps. Avoid over-mixing to ensure light, fluffy pancakes.
Heat a non-stick skillet over medium heat and melt ½ teaspoon of butter. Once melted, wipe most of the butter from the pan with a paper towel to prevent excess browning.
Remove three Nutella discs from the freezer just before cooking to keep them firm. Pour ¼ cup of batter into the skillet and immediately place a frozen Nutella disc in the center. Quickly cover the disc with a little more batter to seal it inside.
Cook until bubbles form around the edges and the underside is golden brown, approximately 2 minutes. Carefully flip and cook the other side until golden.
Repeat with the remaining batter and Nutella discs. Refresh the skillet with additional butter after every third or fourth pancake if needed. You should yield about seven pancakes, though the final count can vary depending on how much batter is used for sealing.
Serve the pancakes warm, optionally topped with fresh sliced strawberries. They’re delightful on their own, but a dollop of whipped cream could be added if desired—though many find these indulgent treats perfect as they are.