Light Vanilla Magic Cake

📝 Ingredients

• 4 eggs
• 100 g caster sugar
• 60 g unsalted butter
• 100 g plain flour
• 500 ml semi-skimmed milk
• 1 tsp vanilla extract
• 1 pinch of salt

🍴 Utensils

• 20 cm square tin
• Baking paper
• Electric hand mixer
• Whisk
• 2 mixing bowls
• Saucepan

📖 Steps

1. Preheat the oven to 150 °C (140 °C fan). Line the tin with baking paper, leaving it overhanging the edges (don't use a springform tin: the very runny batter would leak). Melt the butter in the saucepan over a very low heat, pour it into a bowl and leave to cool slightly.
2. Warm the milk in the same saucepan over a low heat to about 40 °C (you should be able to dip a finger in without burning yourself), then add the vanilla extract. Carefully separate the whites from the yolks: the slightest trace of yolk would stop the whites from whipping up.
3. In a large bowl, whisk the yolks with the sugar for 2 to 3 minutes, until the mixture turns pale and frothy. Add the lukewarm melted butter and whisk again.
4. Add the flour all at once and whisk until there are no lumps left. Then pour in the warm milk a little at a time, whisking constantly: the batter should be very runny, like a thin pancake batter — that's normal.
5. In another very clean bowl, whisk the whites to stiff peaks with the pinch of salt using an electric mixer, first on low speed then faster. They're ready when they form a firm peak on the end of the whisk and don't slide when you tilt the bowl.
6. Add the whites to the batter in three additions, mixing gently with the whisk, just enough to distribute them: small flecks of white should remain on the surface. Overmixing would stop the three layers from forming.
7. Pour into the tin and bake for about 55 minutes. The top should be golden and the centre still slightly wobbly when you gently shake the tin: the cake firms up as it cools.
8. Leave to cool completely at room temperature, then refrigerate for at least 3 hours, ideally overnight. Lift out of the tin using the paper, cut into 8 slices with a knife dipped in hot water and serve well chilled.