Apple strudel and dumplings are iconic German desserts, and in Germany they often come with vanilla sauce on top. The Germans love this sweet, custardy sauce so much they also dollop it on cake and ice cream. It's served warm or cold, depending on what you are putting it on. Germans generally use it instead of whipped cream, but sometimes they do a double topping hit and use both vanilla sauce and whipped cream. On top of whichever sweet these are paired with, it makes a triple threat of delicious.
It’s a thin egg custard and especially good if you make it with real vanilla and eggs. If you don't want to go to the effort of homemade vanilla sauce, you can get a similar topping by cooking up packaged vanilla pudding using 3 cups of milk instead of two.
- Beat the egg yolks, sugar and vanilla sugar if you are using that (do not add vanilla extract until later) together until the yolks are thick and pale yellow and the sugar is dissolved, about 4 minutes.
- Bring the milk to a boil in a heavy 2-quart saucepan and then pour over the egg yolks and sugar mixture in a thin stream, using a whisk or electric mixer to stir constantly.
- Pour the mixture back into pan and heat without boiling until it coats the back of a spoon.
- Remove the pan from the heat and stir in vanilla extract if you are using it instead of the vanilla sugar.
- Serve the sauce warm or cold.
If you this recipe difficult to make, you might want to cook the egg yolk-milk mixture in a double boiler, which heats gently and makes it easier to heat the sauce without letting it boil. Boil 2 inches of water in the bottom pan of the double boiler and cook the custard over that, stirring constantly. See this photo series on how to make a cream sauce in a double boiler for some tips that could help with using a double boiler to make vanilla sauce.
You might also choose to have a bowl of ice water standing by to place the saucepan in if you heat it too much and want to stop the sauce from boiling. Place the pan in the ice water if it looks like it’s curdling and stir briskly until it smooths out.
See a recipe for a cornstarch-thickened sauce here.