Directions

1. Spray eight 6-ounce ovenproof custard cups (such as Pyrex) with vegetable cooking spray. Set them in two 9-inch round or square baking pans. Bring 1 1/2 quarts of water to boil in a tea kettle. Heat oven to 325 degrees.
2. Whisk butter, 1/2 cup sugar and zest until smooth. Whisk in egg yolks, then flour, until smooth. Next whisk in 1/4 cup orange juice and 2 Tbs. lemon juice, then the milk, to form a thin batter.
3. In a separate bowl, beat egg whites with a hand mixer until foamy. Gradually add remaining 1/4 cup sugar, until the whites are stiff enough to hold a peak. Gently fold the whites into the batter until just smooth.
4. Pour batter into each custard cup. Place pans on oven rack, then carefully pour hot water into each pan, being sure to avoid getting any water on the cakes. Bake until tops are golden brown and spring back to the touch, about 25 to 35 minutes. Remove pans from oven; let custard cups stand in the water until just warm. Place a dessert plate over each custard cup; invert cake onto plate. Mix marmalade, liqueur and remaining 2 Tbs. lemon juice. Spoon sauce over cakes.