Method:

• Heat oven to 350°F (325°F for dark or nonstick pan). Generously spray bottom only of 8- or 9-inch round cake pan with cooking spray (without flour).
• In large bowl, beat cake ingredients with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Pour into pan.
• Bake 43 to 48 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes. Run knife around edge of pan to loosen cake; remove from pan to cooling rack. Cool completely, about 1 hour.
• Meanwhile, in 1-quart heavy saucepan, mix sugar and cornstarch. Gradually stir in orange juice, 1/4 cup water and the egg yolks. Cook over medium heat, stirring constantly, until thickened. Cook and stir 1 minute longer. Remove from heat; stir in 2 tablespoons butter and the orange peel. Transfer filling to small bowl. Cover; refrigerate 30 minutes.
• In medium bowl, place chocolate. In 1-quart saucepan, heat whipping cream and 4 teaspoons butter over medium heat until butter melts and mixture boils. Pour cream mixture over chocolate; stir until smooth. Cool 10 minutes or until room temperature.
• Split cake horizontally to make 2 layers. On cut side of bottom layer, spread filling; cover with top layer. Pour glaze over top of cake; spread glaze to edge of cake and allow to drizzle down side of cake. Store in refrigerator.