CAKE "Pani Valevskaya"

Cake "Pani Valevskaya"
Sand dough:
4 egg yolks
330 gr. wheat flour, top grade
1 tsp baking powder
a pinch of salt
40 gr. powdered sugar
170 gr. butter, cold
1.5 - 2 tbsp. sour cream 20%
Meringue:
4 egg whites
200 gr. powdered sugar or fine sugar
2 tsp. starch (i have corn)
80 gr. almond (or other nuts)
a pinch of salt
Custard:
360 ml. of milk
2 tbsp. starch
1 egg
2 tbsp. l sugar
140 gr. butter, 82%
4 gr. vanilla sugar
300 gr. currant jam