Sift the flour with 1 cup sugar into a bowl. In another bowl, beat the egg whites into a light snow and add the lemon juice and salt while stirring. Slowly add 3/4 cup sugar, beating until you get a soft snow. Add the vanilla and almond extract, beating briefly.
The snow must not harden but remain soft and fluffy. Add the sifted flour and sugar gradually and gently stir with a spatula to mix. Pour the mixture into a dry oven dish or cake form, smoothing the top out and put it to bake for 35-40 minutes in a moderately hot, preheated oven.
Invert the ready English sponge cake immediately onto a cooking grid (not a tray). Once cool, release it from the form onto a suitable tray. Serve decorated as desired.