In a bowl using rubber spatula or wooden spoon mix sour cream, lard or butter, pinch of salt and flour until the dough comes together (you can use a stand mixer with paddle attachment if you own one).

Transfer the dough to a floured work surface and knead the dough until smooth. Continue flouring the surface until the dough is not sticky anymore. It should be soft but not sticky (if it is too sticky add more flour). Wrap in a plastic foil and put it in the refrigerator for 1 hour.

Preheat oven to 180 C (350 F). Line baking sheets with parchment paper.

Again, flour the work surface and roll the dough a few millimeters thick (less than 1/4 inch).

Using a glass or larger round cookie cutter, cut the dough into circles.

Fill every circle with about 1/2 - 1 teaspoon (depending on the size of your dough circle) of jam of your choice, fold the circle in half, and press edges with a fork.

Transfer to a baking sheet lined with parchment paper and bake around 10 minutes, or until edges begin to brown, but the top of the cookie is still white. Don't over bake it.

Remove from the oven and while still hot roll in powdered sugar.

Stored in a sealed container, the cookies will keep for several weeks (but I guarantee you, they would not last that long).