Preheat oven to 425 degrees. In a medium cast-iron or ovenproof nonstick skillet, melt 2 tablespoons butter over medium heat; set aside.
In a blender, combine eggs, milk, flour, salt, vanilla, and 1/4 cup sugar. Blend until foamy, about 1 minute. Pour batter into skillet; bake until pancake is puffed and lightly browned, about 20 minutes.
Working quickly, dot pancake with 1 tablespoon butter, and sprinkle with 1 tablespoon sugar and lemon juice. Slice into wedges, and serve immediately.