My great-grandmother taught me how to make this cotton cake with condensed milk, without wheat flour.

Beat the egg whites with an electric mixer until stiff peaks form and they have doubled in volume.
In the same bowl, beat the egg yolks, condensed milk, and cornstarch until light and smooth.
Gently fold the beaten egg whites into the cream using a spatula, using an upward motion.
Pour the batter into a greased and cornstarch-dusted cake pan.
Bake in a preheated oven at 180°C (350°F) for about 20 to 25 minutes, or until lightly golden.
Test with a toothpick: if it comes out clean, the cake is ready.
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