Make the caramel. In a small saucepan over medium-low heat, combine sugar and water. Melt sugar until golden amber in color. Carefully pour hot syrup into a round baking pan, turning the pans to evenly coat the bottom and sides. Set aside.
Create the custard: Combine milk, egg yolks, and sugar in a mixing bowl. Stir the ingredients until everything is properly distributed. Pour the custard mixture on the baking pan with caramel. Set aside
Preheat the oven to 350 degrees.
Create the egg yolk mixture. In a large bowl, Whisk together flour, half of 3/4 cup sugar, baking powder, and salt. Add oil, egg yolks, and milk. Mix well until smooth. Set aside the mixture.
Create the meringue: Beat egg whites with a mixer on high speed until foamy. Add cream of tartar beat until soft peaks form. Gradually add remaining 3/4 cup granulated sugar, beating until stiff, glossy peaks form.
Gently fold the cake mixture into the meringue until well blended.
Pour cake batter over custard mixture in the round baking pan.
Place the baking pan in a baking tray. Pour about 1 cup of hot water on the baking tray.
Bake for about 25 to 30 minutes or until the toothpick test indicates that the cake is ready.
Remove cake from the oven and allow the temperature to cool down.
Slide a small knife around the edges and side of the pan. Release the cake. Serve and enjoy.