Step 1

Melt butter in a 10-in. cast-iron or ovenproof skillet. Sprinkle brown sugar over butter. Arrange plum halves, cut side down, in a single layer over sugar.

Step 2

In a large bowl, beat eggs until thick and lemon-colored; gradually beat in sugar. Combine the flour, baking powder and salt; add to egg mixture and mix well. Blend water and lemon extract; beat into batter. Pour over plums.

Step 3

Bake at 350° until a toothpick inserted in the center comes out clean, 40-45 minutes. Immediately invert onto a serving plate. Serve warm, with whipped cream if desired.