1/2 cup unsalted butter
1/2 cup unsalted brown sugar
1 tablespoon creme de cacao liqueur
1 cup orange juice
1 1/2 cups water
1 1/2 teaspoons lemon juice
1 teaspoon vanilla extract
Melt butter and brown sugar in large saucepan over medium heat. Stir in creme de cacao and orange juice. Bring to a boil, stirring occasionally. Pour over chocolate mixture; remove from heat. Mix together wet ingredients with a serving bowl. Spoon mixture into cake, covering and leaving a 2 to 3 inch musty area in the edges to allow steam to escape.
Bake in preheated oven for 30 minutes, or until center of the cake springs back when touched. Allow to cool entirely, and frost with orange lemon spreads or lemon Frosting or Lemon Filling Cream.
Butterscotch frosting: Whip cream frequently until stiff peaks form. Add lemon liqueur and orange juice; beat until frothy. Fold corn syrup into whipped cream. Spread frosting over top of cake and softly spread 2 or 3 tablespoons over edge and sides near the top of the cake. Fade into cream or pastels.