Soft flour, sugar, baking powder and salt into mixing bowl. Drop in Spry. Add milk and vanilla and beat 200 strokes (2 minutes by hand or on mixer on low speed). Divide batter in half. Add grated orange rind to one batter, and melted chocolate to the other, blending well. Arrange batters, alternatively by tablespoonfuls, in 12x8x2-inch Spry-coated pan.
Run knife through batters several times, both lengthwise and crosswise of pan for a mottled effect. Bake in a moderately hot oven (375 degrees) for 35-45 minutes. Frost cake all over; decorate corners and center with “choco-o-lanterns,” (orange sugar patties with faces made of melted chocolate). Serve with chocolate ice cream and orange sherbet.
Combine 1/2 teaspoon grated orange rind and 3 tablespoons orange juice; let stand 10 minutes; strain. Have ready 3 cups sifted confectioners’ sugar. Bland 1 tablespoon each Spry and butter. Beat in 1/2 cup sugar gradually. Add 1-1/2 ounces chocolate, melted. Stir in remaining sugar alternating with orange juice. Add about 3-1/2 tablespoons scalded evaporated milk or light cream and beat well.