Recipe via Real Simple
1/2 cup flour
1/2 cup milk (I used skim)
1/4 teaspoon kosher salt
1/2 teaspoon vanilla extract
2 tablespoons unsalted butter
2 tablespoons fresh lemon juice (optional)
Fruit jam or jelly (any flavor will work, I used pear preserves)
1 Heat oven to 400 degrees F. In a large bowl, whisk the eggs to combine. Add the flour and whisk until smooth. Add milk, salt, and vanilla and mix through.
2 Add butter to a large cast-iron pan and place in middle rack in the oven until the butter has melted. Remove pan from the oven and immediately pour batter into the hot skillet. Return the pan into the oven and bake until puffed and golden, about 15 minutes.
3 Drizzle lemon juice over the pancake, spread the jam/jelly evenly and sprinkle with powdered sugar.