Raspberry Chocolate Chiffon Cake

Raspberry Sauce
1/2 cup cocoa
3/4 cup boiling water
1 3/4 cups cake flour
1 3/4 cups granulated sugar
1 1/2 teaspoons baking soda
1 teaspoon salt
1/2 cup vegetable oil
2 teaspoons vanilla extract
7 egg yolks
1 cup egg whites (7 to 8)
1/2 teaspoon cream of tartar
4 cups frozen whipped cream, thawed

Prepare Raspberry Sauce; refrigerate at least 1 hour.

Mix cocoa and water; cool.

Heat oven to 325 degrees F.

Mix flour, sugar, baking soda and salt. Beat oil, vanilla, yolks and cocoa mixture until smooth. Beat whites and cream of tartar in large bowl, until very stiff peaks form; gradually pour yolk mixture over whites, folding just until blended. Pour into ungreased tube pan, 10 x 4-inches. Bake on lowest oven rack until top springs back when touched, 65 to 70 minutes.

Invert on heat proof funnel; let hand until cake is cold. Cut cake horizontally into 3 layers. Spread 1 1/3 cups whipped topping and scant 1/2 cup raspberry sauce between each layer and over top of cake. Refrigerate any remaining cake.

Raspberry Sauce:
1 (10 ounce) package frozen raspberries,
    thawed (reserve liquid)
Water (if needed)
1/4 cup granulated sugar
2 tablespoons cornstarch
2 tablespoons orange juice

Drain one package frozen raspberries, thawed. Reserve liquid. If necessary add water to liquid to make 2/3 cup. Mix 1/4 cup sugar and 2 tablespoons cornstarch in saucepan; stir in raspberry liquid. Heat over medium-low heat, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute. Stir in 2 tablespoons orange juice and raspberries.