1kg sweet potatoes, puréed
3 cups (750 ml) milk
1 cup (200 g ) sugar
70g butter at room temperature
4 egg yolks
4 egg whites
½ cup walnuts, chopped
1 teaspoon ground cinnamon
Peel and slice sweet potatoes.
Boil them in the milk until soft.
Purée and mix with sugar, butter, egg yolks, nuts and cinnamon.
Whisk egg whites with a pinch of salt until they form stiff peaks and fold into the mixture. Cover the sides of a loaf tin with caramel (prepared with ½ cup sugar over heat until golden).
Pour the batter into the tin and cook in the oven over a bigger tin with 2 to 3 cm of water, for approx. 45 minutes.
Remove from oven.
Cool for a few minutes inside the tin and turn out.