1 tbsp baking powder
1 tsp salt
1 1/3 cups sugar
1/2 cup canola oil
5 large eggs, separated
3/4 cup orange juice
3 tbsp orange zest
1/2 tsp cream of tartar
Orange Icebox Pie Filling (recipe below)
Orange Buttercream Frosting (recipe below)
Preheat oven to 350 degrees.
Grease and flour 3 9-inch round cake pans; set aside.
In mixer bowl combine the flour, baking powder, salt, and sugar; make a well in the center. Add the oil, egg yolks, and orange juice to the well; beat at medium-high speed 3 to 4 minutes or until smooth. Stir in the orange zest.
In a cold mixer bowl beat the egg whites and cream of tartar at medium-high speed until stiff peaks form. Gently fold the whites into the flour mixture. Spoon the batter evenly into the prepared pans.
Bake cakes for 18 to 20 minutes at 350 degrees until a wooden toothpick inserted in the centers comes out clean. Remove from oven and cool on wire racks in the pans for 10 minutes; remove from pans and allow layers to cool completely on wire racks.
ORANGE ICEBOX PIE FILLING:
3/4 cup milk
1/4 cup cornstarch
1 can (14-oz) sweetened condensed milk
3 large eggs
1/2 cup thawed frozen orange juice concentrate
2 drops red liquid food coloring
4 drops yellow liquid food coloring
3 tbsp butter
1 tbsp freshly grated orange zest
Whisk together the milk and cornstarch in a 3-quart heavy saucepan; whisk until cornstarch is dissolved.
Whisk in the milk and eggs until blended; whisk in orange juice and food colorings. Bring to a boil over medium heat while constantly whisking.
Bring the mixture to a boil and boil 1 minute continuing to whisk constantly. Remove from the heat. Whisk in the butter and orange zest.
Pour the filling into a deep bowl. Place the bowl into a larger bowl filled with ice. Stir often for 10 minutes or until cooled.
Place 1 cake layer on cake plate and top with 1/3 of the filling. Top with another layer and another third of the filling. Repeat with the last layer and filling. Cover and refrigerate at least 4 hours.
ORANGE BUTTERCREAM FROSTING:
1/2 cup butter, softened
1 pkg (16-oz) powdered sugar, divided
1/3 cup milk
2 tbsp freshly grated orange zest
Beat butter at medium speed of electric mixer until creamy. Gradually add 1 cup of the powdered sugar to the butter; beat at low speed until blended.
Add the milk, beating until blended. Gradually beat in the remaining powdered sugar. Stir in the orange zest.
Use frosting to frost the sides of the cake.
Note: This cake can be completed completely and frozen in a protective container for up to 1 month!