Recipe from site Tudo Gostoso.
3 large eggs, divided in egg white and yolk
180g butter at room temperature (I used unsalted)
1 cup flour
1 tbsp baking powder
2/3 of 1 can (395g) sweetened condensed milk
1. Preheat the oven to 350F. Grease and flour a small round pan.
2. In a eletric beater, whip the egg whites until is in soft peaks, but not stiff. Reserve in fridge. On the same bowl that you whip the egg whites, beat the butter and yolks for about 7 minutes or until is really creamy and fluffy. Add flour and baking powder and beat over low speed for 30 seconds. Beat in sweetened condensed milk just until is incorporated. Gently fold in whipped egg whites. Pour the batter into the prepared pan and bake for about 30-35 minutes or until a toothpick is inserted in the center comes out clean.
Cook's tip: You can moist the cake with the leftover of condensed milk stirred with 4 tbsp water. You can cover the cake with fruit jam, chocolate ganache, Nutella, melted chocolate or use melted goiabada (brazilizan guava paste) stirred with a little water.