One ingredient that may be a little hard to find is vanilla sugar. This product is made from dextrose, (sugar) and vanilla flavor. I found it at Andronico's, a local grocery store, but I think you can find it at Cost Plus, and certainly on-line.
I made my cookies a little on the thick side- so my sandwiches are a mouthful. I had homemade cherry and strawberry jam in my fridge- no currant jelly- so I did half cherry, half strawberry. I put about a 1/4 cup of each in a small saucepan over low heat, and cooked it down to a syrup. Then I pressed it through a small sieve to take out the solid chunks of fruit.
4 hard boiled eggs, yolks only
120 g powder sugar 4.2 oz
200 g butter 7 oz
2 packages vanilla sugar
1 dash of salt
300 g flour sifted 10.6 oz
120 g almonds coarsely chopped 4.2 oz
100 g sugar 3.5 oz
2 raw egg yolks
½ cup currant jelly or currant jam
Hard boil eggs and put egg yolks through fine sieve. Stir in 80 g (2.8 oz) powder sugar and butter till creamy. Add vanilla sugar, salt and flour and kneed into dough. Wrap in plastic wrap and let rest for 2 hours in refrigerator.
Preheat oven to 200 C. – 390 F
Meanwhile mix sugar and chopped almonds. Beat raw egg yolks.
Roll out dough to 4mm and cut our rings or round cookies. Brush on one side with egg mixture, press into almond and sugar mixture and bake top up for ca. 10 to 15 minutes. Carefully remove cookies and let cool. Brush underside with warmed and stirred currant jelly or jam and put two rings together. Dust with remaining powder sugar.