Ugent! Recipe needed for huge sponge cake

[Grockle]

i bake a lot so am fine with normal quantities but I know I can't double the recipe forever... Does anyone know what quantities I need to make a 30 x 40cm cake please? I need to bake it in the morning. I am fairly sure that in the past I've just made 4 batches of sponge cake and baked that but I'm not convinced.

[RockStockAndTwoOpenBottles]

16oz SR flour, sugar, butter and 8 eggs is spot on for that size.

[BikeRunSki]

You'll need to cook it cooler for longer too, or the edges will burn and the middle will be raw.

[RockStockAndTwoOpenBottles]

I cook this one for about 25-30 minutes at 190.

[4merlyknownasSHD]

I have just had a PM from another mumsnetter who used this recipe when I posted it last year. She said that it was delicious. 30cm x 40cm is basically 12 inches x 16 inches so you could increase the mix by 1/3rd. It shouldn't make any real difference to the cooking time as the middle of the cake is still 6 inches from the side.

Madeira Cake - 12? Square (Cooking time 65 mins)

Ingredients:

825 gm Butter
825 gm Self Raising Flour
825 gm Caster Sugar
12 Large Eggs


Method:

Pre-heat the oven to 180 deg. (Gas Mark 4)

Grease and line the pan (Triple lining is suggested to prevent scorching).

Take a LARGE mixing bowl, cream the butter and sugar. Then add the eggs, one at a time to prevent curdling (you may need to add a little flour from time to time). Once the eggs are mixed in, fold in the balance of the flour.

Cook for 30 minutes at 180 deg. then cover with baking parchment for another 20 minutes at the same temperature. For the final 15 minutes, keep covered but reduce the temperature to 170 deg. (Gas 3).

This should produce a cake that has a close, even texture, is completely cooked and moist.

[4merlyknownasSHD]

Alternatively, bake smaller cakes and join them up under the icing.......less risk of burning the edges and having a soggy middle.

[Grockle]

Perfect, thank you. Will bake it tonight - work got in the way today!

[Grockle]

I did it -I weighed 9 eggs and did the same weight of flour, butter, sugar. It took ages to cook but looks good. Now to make it into a magicians table!

[Jackeyd67]

I have just made this today as per your measurements and timing, it has turned out perfect (not tasted yet) feels and looks perfect, first time I have had a cake be ready dead on time. Thanks