To make the dough:
Mix everything together; knead dough on counter with more flour until a smooth dough is formed. Let dough rest on counter covered with bowl it was mixed in, for 20 minutes. This resting time is needed so that dough will become soft enough to roll.
Roll out dough on a floured counter as thin as possible. Use fingers to gently stretch out thick parts of dough.
Brush dough with melted butter. Sprinkle the filling ingredients all over dough ending with apples. Squeeze lemon over apples.
Carefully roll up dough, ending with seam on the bottom, place on a parchment covered cookie sheet. Bend into a horseshoe if it doesn’t fit.
Brush generously with melted butter.
Bake at 350 °F for about 45 to 60 minutes until the strudel is a nice golden brown.
Sprinkle generously with icing sugar before serving or when strudel has cooled.