Orange chiffon cake

9 large eggs, room temperature, separated

1 cup sugar, divided

1/4 cup orange juice

4 teaspoons grated orange zest

1 cup plus 2 tablespoons all-purpose flour

1 teaspoon cream of tartar

1/2 teaspoon salt

FILLING:

1 cup sugar

1/4 cup all-purpose flour

1/4 teaspoon salt

1/2 cup orange juice

1 large egg, lightly beaten

4 teaspoons grated orange zest

1 carton (12 ounces) frozen whipped topping, thawed

• Place egg whites in a large bowl; let stand at room temperature for 30 minutes. In another large bowl, beat egg yolks until slightly thickened. Gradually add 1/3 cup sugar, beating until thick and lemon-colored. Blend in orange juice and zest. Add flour and remaining sugar to yolk mixture; mix well.
• Add cream of tartar and salt to egg whites; beat with clean beaters until stiff peaks form. Fold into batter. Gently spoon into an ungreased 10-in. tube pan. Cut through batter with a knife to remove air pockets.
• Bake at 325° on lowest oven rack 40-50 minutes or until top springs back when lightly touched. Immediately invert pan; cool completely, about 1-1/2 hours. Run a knife around sides and center tube of pan; remove cake.
• For filling, in a double boiler or a metal bowl over simmering water, combine the sugar, flour and salt. Add the orange juice, egg and orange zest. Constantly whisk until mixture reaches 160° or is thick enough to coat the back of a spoon. Remove from heat and cool completely. Fold in whipped topping.
• Cut cake horizontally into 3 layers. Place bottom layer on a serving plate; top with one-third of the filling. Repeat layers twice. Serve immediately or refrigerate.

https://www.tasteofhome.com/recipes/orange-cream-chiffon-cake/