FOR THE CAKE: Add cream of tartar to the egg whites and beat at high speed until foamy. Gradually add 3/4 cup sugar, continuing to beat until stiff peaks form.
Beat 3/4 cup sugar together with egg yolks.
Sift together dry ingredients. Add to the egg yolk mixture ALTERNATELY with the fruit juice or water, orange peel and flavouring. Mix until blended and beat 1 minutes. Batter will be stiff. Put a large spoonful of egg whites into the batter and beat to make batter a little less stiffer and then FOLD in the rest of the egg whites gently.
Pour batter into 2 (8 or 9-inch) layer cake pans (or use springform pans) (I like to put parchment paper on bottom of pan) and bake in preheated 350°F oven until toothpick inserted in centre comes out clean about 30 to 35 minutes. Cool in pan and gently go round with knife and remove from pan and slice to make 4 layers.
Sprinkle each layer of chocolate sponge cake with cherry liqueur.
Blend the butter, icing sugar and coffee until creamy and spreadable. Spread 1/3 over bottom layer of cake. Press 1/3 cherries into this filling. Place another cake layer on top and repeat. Put fourth layer on top.
Whip the cream. Add 1/4 cup sugar and vanilla. Slather whipped cream on top and sides of cake. Decorate with a few cherries add chocolate curls. Pipe rosettes around cake and add a cherry on top of each rosette and decorate in centre with chocolate curls.