Make the pastry: in a bowl, mix together the flour, eggs, salt and water. Mix well. Divide the dough into four, shape into disks, wrap in plastic wrap and let rest 1 hour.
Preheat oven to 180 degrees C and butter a baking dish.
Roll out the dough on a floured surface to make four rectangles. Brush with melted butter, then some of the cream. Evenly distribute the apples and raisin, leaving a margin at the edge. Sprinkle with sugar to taste, then roll up the strudels.
Place the strudels next to each other in the baking dish and bake 40 minutes. Brush the tops with the sour cream and bake another 20 minutes.