Hand kneading creates a soft, supple, and glutinous dough that is easy to stretch until it's so thin you can see through it. A cloth lets you easily roll up the strudel. Toasted bread crumbs soak up the juices from the apples. Tossing the apple mixture just before using makes it easier to work with. Rolling the strudel onto parchment paper makes it easy to transfer the strudel to the pan. Toasted ground hazelnuts are sprinkled over the dough for additional flavor and texture. Apple strudel is a classic dessert from Eastern Europe. The German word  strudel  literally means "whirlpool," and it refers to the technique and effect of rolling up a generous fruit filling in a paper-thin unleavened dough. Since landing in Berlin a few weeks ago, I've been sampling apple strudel whenever I can. Strudel dough has a reputation for being difficult. After an un-yeasted dough of flour, water, and oil (or butter) is kneaded, it is rolled out and stretched until so thin you can read a newspaper through it.…