chocolate sponge cake recipe for 2x 8 inch square sandwich tin

[CheeringBell]

Can anyone help? I want to make a chocolate birthday cake. It needs to be a fairly light sponge cake as my lot a really fussy. I've heard that a recipe for a 9inch round cake will work in a 8inch square but I can't find one anywhere.

Thanks

Whisk 6ozs caster sugar with 4 medium eggs till really pale and frothy. Add 4ozs sieved plain flour and 2 tablespoons of cocoa and mix gently. Sprinkle 2 rounded teaspoons of baking powder onto the top of this mix. Pour 4fluid ozs of milk heated to boiling point with 1oz melted butter and allow the bp to froth up. Mix in then pour into lined, greased and very lightly floured sandwich tins. (The mixture will be alarmingly sloppy but that's ok). Bake at 175 for approx 30 mins. Odd recipe but gives fantastic results.
Sandwich and top with choc fudge icing.

Thanks - will have to try this!