Preheat the oven to 150 ° C (top / bottom heat). Mix the 4 egg yolks with the powdered sugar, salt and vanilla sugar until they are white. Fold the rum and almonds into the mixture.
Use a piping bag to squirt the macaroon mixture onto a baking sheet lined with baking paper. Bake on the 2nd rail from the bottom for about 20 minutes.
If you want, you can also spray the macaroon mixture on wafers before baking and place whole almonds on top of the piles.