Past dough:
In a bowl, mix the flour with the salt
Add the butter cubes. Using a pastry blender, two knives or your fingers, incorporate the butter into the flour until the mixture forms pea-sized lumps
Add the sour cream. Using two forks, work the dough until it is homogeneous
Wrap it in plastic wrap and refrigerate for 30 minutes.

Filling:
Melt a little butter in a saucepan and add the apple slices.
Sprinkle with sugar and mix over high heat, then add the raisins, hazelnuts, almonds, and cinnamon.
Let it stew over medium heat, remove from heat and let cool.

Preheat the oven to 400 F (200 C).
Roll out the dough into a 12″ x 16″ (30 cm x 40 cm) rectangle.

Pour the apple filling over the dough and spread it evenly with a spatula.
Roll the dough quickly into a log without squeezing too much.
Place the roll of dough on a silpat-lined baking sheet.
Bake in the oven for 35 to 45 minutes.

Sprinkle with powdered sugar before cutting into slices.