Preheat oven to 350 degrees F (175 degrees C).
Sift the cake flour, sugar, and salt together three times, then combine with the boiling water. Let the mixture stand to cool.
Using a mixer, beat the egg whites, cream of tartar, baking powder, vanilla, and almond flavouring until stiff peaks form. Gently mix this into the cooled flour mixture and pour the batter into an ungreased 12x18 inch baking pan.
Put the cake in the preheated oven and bake for 35 minutes. Once finished, cool the cake inverted in the pan while laying a tea towel underneath to absorb the steam. Finally, frost the cake when it is completely cooled.
