Preheat the oven to 450 F.
In a mixing bowl, whisk together 2 Tbsp melted butter, milk, eggs, lemon juice, vanilla, and lemon zest. Then add the flour, sugar, and salt. Whisk well until batter is smooth.
Melt 2 Tbsp butter on a cast iron skillet or oven-proof skillet. Add the blueberries to the melted butter and let simmer for 1-2 minutes. Pour the prepared batter over the top.
Transfer the cast iron skillet or oven-proof skillet with blueberries and batter to the preheated oven. Bake for 15 to 18 minutes, or until the pancake is golden brown and set in the middle.
Let cool slightly before slicing and serving with a dusting of powdered sugar or a drizzle of maple syrup. Enjoy!