Preheat the air fryer to 400 degrees F (200 degrees C). In a 6-inch baking dish, add the butter. Place in the air fryer for 2 minutes, or until the butter has melted.
Meanwhile, in a blender, add the eggs, milk, flour, salt, vanilla, and sugar. Blend for about 1 minute, until the mixture is frothy. Pour the batter into the warmed dish and bake for 8-12 minutes, until the pancake is lightly browned and puffed.
Carefully remove the pancake from the dish, garnish with powdered sugar, and squeeze a lemon over the top. Serve immediately.