I posted an old family recipe for Hot Milk Sponge cake on this blog a few years ago. It has 2 eggs rather than the 7 in the original recipe. I used our recipe and it was just fine!
Here is the link to the hot milk sponge cake recipe.
Custard Cream:
4 large egg yolks½ cup sugar
¼ cup cornstarch
¼ teaspoon salt
1½ cups milk ( I used 1 cup whole milk and 1/2 cup heavy cream)
1 tablespoon vanilla extract
2 tablespoons butter
Whisk the eggs, sugar, cornstarch, and salt in a medium saucepan until well combined and no lumps remain.
Then whisk in the milk until well combined. Heat the mixture over medium-high heat for 2 to 4 minutes, or until thickened stirring constantly.
Remove from heat and add the vanilla. Add the pieces of butter, and stir until melted.
Pour the custard into a bowl and refrigerate until thoroughly chilled.