Fruit-enclosed pastries are natural to the Pennsylvania Dutch. Apfelstrudel in its original form is made with a thinly stretched dough filled with a mixture of apples, sugar, and spices. Raisins, nuts, chopped candied citron, or cherries are sometimes added to the strudel. To stretch the strudel dough, it is helpful to have at least two extra sets of hands (invite your friends to a "strudel stretch").
To prepare pastry, put flour into a large bowl and make a well in the center. Combine the eggs, salt, oil, and water. Whip mixture with a fork until blended, and pour into the well of flour. Stir until a soft dough forms.
Pick up the dough with one hand and slap it into the bowl or onto a breadboard about 100 times, or until it becomes very elastic and is no longer wet and sticky but leaves the board and your hands clean. The dough is very sticky in the beginning, but as you work with it, it becomes less sticky. Let dough rest for 5 to 10 minutes.
Cover a table with a clean tablecloth or sheet (a round table about 5 feet in diameter is ideal). Dust lightly with flour. Dust the ball of dough with flour, and place it in the center of the cloth. Roll out the dough with a rolling pin to make a circle about 20 inches in diameter.
Starting with one person stretching the dough, reach under the dough with palms up. Turn hands sideways making fists of your hands, and very slowly rotate fists outward under the dough to stretch it. When it is about 24 inches in diameter, set dough back onto the cloth.
At this point, it is helpful to have several sets of hands working. Very carefully, hands under the dough with palms up and fingers straight out (not curved upward), stretch the dough evenly and very slowly from the center outward. Keep pulling evenly in all directions until it is tissue-thin and almost transparent. It should be about as thin as the membrane of an egg. The dough should be 4 to 5 feet in diameter. A thick edge will remain; cut it away with a knife and save it for making noodles.
Preheat oven to 400°F.
Brush dough all over with 1⁄2 cup melted butter and sprinkle with toasted bread crumbs or cinnamon sugar.
To make the filling, put the apple slices in a mixing bowl. Sprinkle with the lemon juice, sugar, cinnamon, and a dash of nutmeg. Toss lightly.
Sprinkle filling over two-thirds of the dough, leaving one-third free (this will be the end of the roll). Fold the two sides perpendicular to the free end about 4 or 5 inches over the filling, to hold it in the ends when the strudel is rolled.
Starting with the filled end, gently lift the cloth to roll the strudel, rolling toward the empty end. Place the roll on a buttered cookie sheet, bending it into a horseshoe or wreath shape. Brush it with about 1 tablespoon melted butter, and bake 35 to 45 minutes, or until golden brown.
CHERRY FILLING: Combine two 16-ounce cans drained, pitted sweet cherries with 1⁄2 cup sugar, 1 cup raisins, 1 cup finely chopped toasted almonds, 1 teaspoon grated lemon peel, and 1 teaspoon cinnamon. Mix well.
POPPY-SEED AND ALMOND FILLING: Simmer 1 cup poppy seeds in 1⁄2 cup milk until milk is completely absorbed, about 30 minutes. Whirl 1 cup blanched almonds in a blender or food processor until fine. Add the finely pulverized almonds to the poppy seeds, and mix in 1⁄2 cup honey, 1⁄2 cup sour cream, 1⁄2 cup sugar, 1 cup raisins, 2 teaspoons grated lemon peel, and 1 teaspoon cinnamon.