Beat together eggs and milk until well blended. Add the flour and salt; stir with a fork until just combined. The batter will be a little lumpy.
Melt butter in an oven-proof 12-inch skillet, preferably seasoned cast iron. When the butter sizzles, add the banana slices. Pour the batter on top.
Place in the oven and bake for about 20 minutes, until the pancake is puffed up and golden.
Drizzle the lemon juice over the top, then sift powdered sugar over all. Serve immediately.
Variation: You may substitute 2 sliced peeled tart apples for the bananas. Saute the apple slices in the butter and season with 3 tablespoons sugar, 1/4 teaspoon cinnamon and 2 tablespoons lemon juice before adding the batter.