flavourless oil, for the tin
4 eggs, separated
200g caster sugar
1 tsp vanilla extract
200g plain flour
1 tsp baking powder
410g can evaporated milk
200ml sweetened condensed milk
300ml double cream
2 tbsp icing sugar
Heat oven to 180C/160C fan/ gas 4. Lightly oil and line the base and sides of a 20cm square cake tin.
Put the egg whites in a large bowl with a pinch of salt. Beat with an electric hand whisk until foamy, about 3 mins. Keep mixing while you add 150g of the sugar, a spoonful at a time, until thick and glossy.
In another bowl, mix the egg yolks, remaining sugar and vanilla (no need to clean the beaters first) for 2 mins, or until pale and foamy. Add the flour, baking powder and milk to the egg yolks, and use a spatula to fold everything together.
Add a large spoonful of egg white to the cake mix, beat together to loosen the mixture, then gently fold through the remaining egg whites with a large metal spoon (being careful not to over-stir so you don’t knock out too much air), until you have a smooth batter.
Pour into the tin, smooth the top and bake for 40-45 mins until a skewer inserted into the centre comes out clean. Mix together the evaporated milk, condensed milk and 3 tbsp of the cream.
Whip the remaining cream and icing sugar together until holding soft peaks. Spread the cream over the cake and sprinkle with a little cinnamon. Can be made and chilled a day ahead. Serve in squares with any remaining soaking milk.