Preheat the oven to 160 degrees. Lightly butter a baking dish.
Separate the egg whites and yolks. Put the whites is a large mixing bowl. The yolks in a smaller one.
Add a pinch of salt to the egg whites. Mix using a mixer until you obtain a snow-like thick mixture.
Add the sugar add mix again with a mixer for 5 more minutes.
Mix the egg yolks in a separate bowl with a mixer. Then add the egg yolks to the egg whites slowly and while mixing with the mixer. Also add the vanilla extract.
First sieve the flour and baking powder in a separate bowl. Then slowly add to the eggs, while mixing with a wooden spoon this time. Mix from bottom to top, try not to loose the fluffiness.
When you obtain a smooth mixture, pour it into the baking dish. Try to spread the mixture evenly. If necessary shake slightly to make even.
Bake until the cake is cooked. Check with a tooth pick. Dip the tooth pick in the cake, if it comes out clean it means that the cake is ready, take it out of the oven. It will take about 40 minutes.
Put the butter and the sugar in a skillet. Wait patiently, over low heat, without mixing, until this mixture turns brown. Once the sugar has melted you can mix.
Add the milk and the cream slowly, while mixing really fast. Mix until you obtain a caramel texture. Eventually your effort will pay off.