13/4 cup cake flour
1/2 cup caster sugar, divided
3/4 cup powdered milk
1 tablespoon baking powder
1 teaspoon salt
1/2 cup butter, cut into 16 pieces
1/2 cup canola oil
4 large eggs, separated
1/4 cup condensed milk
1 cup fresh milk
1 tablespoon vanilla extract
3 chocolate trees, for garnish
1/3 cup fresh milk, hot
1 1/4 cup powdered milk
1 teaspoon vanilla extract
3 cups powdered sugar, sifted
1 cup butter, softened
Preheat oven to 325?F. Grease, flour, and line bottoms of 3 6-inch pans.
Meanwhile, sift flour into the bowl of a stand mixer. Add 1/4 cup sugar, powdered milk, baking powder, and salt. With the mixer running, add butter, one piece at a time. Pour in canola oil. Increase speed to Medium until mixture forms clumps. Decrease speed to Low.
In a medium bowl, whisk egg yolks, condensed milk, fresh milk, and vanilla. With mixer running, gradually pour egg mixture into butter mixture. Gradually increase speed to Medium until mixed.
In a mixing bowl, whisk egg whites on Medium-High until soft peaks form. Add remaining sugar; whisk until stiff. Fold into batter in 3 batches using a spatula.
Divide batter evenly among pans. Bake 25 minutes or until a toothpick emerges from cake with a few crumbs. Turn upside down on racks until cool.
Meanwhile, make Milk Buttercream: Mix hot milk and powdered milk; cool. Beat butter on Medium speed. Add milk mixture and vanilla; beat until mixed. Add powdered sugar in batches, beating well after each addition. Increase speed to High; beat until smooth and creamy.
To assemble cake: Spread milk buttercream between layers; cover with crumb coat. Chill until hardened. Frost cake with remaining buttercream. Place white chocolate trees on top of cake. Chill until firm; slice and serve.