Cookbook:Impossible Sponge Cake

Cookbook | Ingredients | Recipes | Desserts

Impossible Sponge Cake

Sponge cake is the most commonly recognised variety of baked confectionery in Britain. It has a sweet taste, often flavoured with vanilla, chocolate or other additions, and can be cut and displayed in a number of different ways.

An easier version of this recipe is available that does not require a kitchen scale.


For the cakeEdit

  • 2 eggs, USDA large (2 to 2.25 oz, 56.6 to 63.7 g) or EU size M (53 to 63 g)

Important: Weigh the eggs and substitute n for the eggs' weight.

  • self-raising flour (n)
  • caster sugar (n)
  • butter (n)
  • sodium bicarbonate (2tsp) (baking powder, baking soda or bicarbonate of soda)

Extras (optional)Edit

  • vanilla extract (1-2 tsp)
  • food colouring (a few drops)
  • chocolate powder (unsweetened baking cocoa) (according to taste. Use 3g less flour for every 4g added.)


Choose one of these to spread between two cakes if making a cake with more than two eggs.

  • 2-4 tbsp jam (softened with pallette knife or similar) or
  • buttercream (cream together 100g caster sugar and 100g butter)


One of the following:

  • 75g icing sugar (superfine)
  • 70g caster sugar (fine)
  • 65g granulated sugar (medium)
  • 55g demerara sugar (large crunchy crystals)


  • 1 large mixing bowl
  • 1 set of scales
  • 1 wooden spoon


  1. Preheat an oven to 200 degrees Centigrade.


  1. Cream together the sugar and butter in the mixing bowl. They should achieve a creamy texture with quite a thick consistency. The longer, harder and faster the butter and sugar are creamed the lighter the cake will be when cooked.
  2. Add both eggs and mix well.
  3. Add all the flour and mix well.
  4. Add any food colouring, flavouring, etc. at this point. If you add liquid ingredients, add the same volume again of sugar and flour mix to compensate. If adding dry ingredients, ensure to use 3g less flour for every 4g of extra dry ingredients added.
  5. Beat with wooden spoon in a circular motion, trying to incorporate as much air as possible.


  1. Grease one or two cake tins with butter.
  2. Spoon, then scrape, as much cake mixture as possible into the tins. If using two tins, try to ensure that each tin contains an equal amount of cake mixture and is not more than 3/4 filled.
  3. Put the tins into the oven and leave them for approximately 10 minutes before checking them. The cooking time should reach around 15 minutes: keep checking them regularly after about 8 minutes since all ovens vary.


One cakeEdit

  1. Turn the cake out onto a wire rack to cool.
  2. When cool, dredge with sugar using a spoon.

Two or more cakesEdit

  1. Turn the cakes out onto a wire rack to cool.
  2. When cool, turn one of them upside down and spread your filling onto it.
  3. Place the other cake (top up) onto the upside-down cake and dredge the cake with sugar using a spoon.