Prepare the cake. beat 3/4 cup sugar and the egg yolks until light and fluffy. Stir in the milk, vanilla extract, flour and baking powder. Beat the egg whites to soft peaks, adding the cream of tartar after 20 seconds. Gradually add the remaining 1/4 cup sugar and continue beating until the whites are glossy and firm, Gently fold the whites into the yolk mixture. Spoon this batter into a 9 X 13 inch greased baking dish.

Bake the cake for 40 to 50 minutes at 350 °F or until it feels firm and an inserted toothpick comes out clean. Let the cake cool for 2 hours. Pierce the cake all over with a fork.

Prepare the milk syrup. combine the evaporated milk, sweetened condensed milk, cream and flavorings and whisk until mixed. Pour the syrup over the cake, spooning the overflow back on top until all is absorbed.

Prepare the meringue. Place all but 2 tablespoons sugar in a heavy saucepan with 1/4 teaspoon cream of tartar and 1/2 cup water. Cook over high heat, covered for 2 minutes. Uncover the pan and cook the sugar to the soft ball stage, 239° on a candy thermometer.

Meanwhile, beat the egg whites to soft peaks with the remaining 1/4 teaspoon cream of tartar. Add the remaining 2 tablespoons of sugar and continue beating to stiff peaks. Pour the boiling sugar syrup in a thin stream into the whites and continue beating until the mixture is cool.

Thickly spread the top and sides of the cake with meringue, using a wet spatula. Sprinkle with cinnamon. Refrigerate the cake at least 2 hours before serving.