Preheat the oven to 180°C / 350°F and grease a cake pan.

Whisk the eggs with 160 g granulated sugar until the mixture is pale, thick, and tripled in volume.

Fold 200 g all-purpose flour into the egg mixture until no dry streaks remain.

Pour the batter into the prepared cake pan and level the surface.

Bake the sponge cake for about 25 minutes, until golden and a skewer inserted in the center comes out clean.

Combine 300 ml milk with 150 ml heavy cream in a measuring jug.

Whisk 200 ml sweetened condensed milk into the milk mixture until smooth.

Poke the warm sponge all over with a skewer and slowly pour the three-milk mixture over it.

Refrigerate the soaked cake for at least 2 hours, until the milk mixture has been absorbed.

Whip 250 g mascarpone with 200 ml heavy cream until lightly thickened.

Add 60 g icing sugar and whip the mascarpone mixture to firm, spreadable peaks.

Spread the mascarpone whipped cream evenly over the chilled cake.

Heat 200 g granulated sugar with 70 ml water in a saucepan until it turns a deep amber caramel.

Remove the caramel from the heat and whisk in 50 g butter until melted.

Whisk in the remaining heavy cream and cool the caramel sauce until it is thick but pourable.

Drizzle the cooled caramel over the cake and refrigerate for 30 minutes before serving.