Preheat your oven to 425°F (220°C). Place your skillet in the oven to heat while you prepare the batter.
In a mixing bowl, whisk together the eggs until well beaten.
Add flour, milk, sugar, vanilla extract, lemon zest, lemon juice, and salt to the beaten eggs. Whisk until the mixture is smooth and well combined.
Carefully remove the hot skillet from the oven. Add the unsalted butter to the skillet and swirl it around to melt and coat the bottom.
Pour the batter into the skillet over the melted butter. Sprinkle the fresh blueberries evenly on top of the batter.
Return the skillet to the oven and bake for 18-20 minutes, or until the pancake is puffed and golden brown.
Once baked, remove from the oven and let it cool for a minute. Serve warm, optionally dusted with powdered sugar and extra lemon wedges on the side.