German Apple Strudel

For dough, mix 2 1/2-3 cups flour, 3 Tbsp. sugar, salt, baking powder, 2 tsp. cinnamon, 3/4 cup butter, and eggs to a soft consistency. Add flour a little at a time as needed until stiff but not sticky. Knead dough about 10 minutes. Do not over mix. Divide dough into 3 equal parts. Grease bowls and put a piece of dough in each bowl, turning to grease the top. Let set for about 1 hour covered. Peel apples. Butter 3 9x13-inch cake pans, any 3 pans as long as they have sides. (This strudel can be frozen for up to 3 months, baked or unbaked.) Mix milk, sour cream, vanilla, and 1 Tbsp. sugar together in a medium bowl until gravy thin. Set aside. Lay out a clean dish towel. Sprinkle with a bit of flour. Roll or stretch out 1 piece of the dough very, very thin (about 1/8 inch thick). Combine apples, raisins, 1 cup sugar, 1 Tbsp. cinnamon, and 1/2 cup flour, and mix well. Using a pastry brush, spread 1/3 of cream mixture on the dough. Using 1/3 of the apple mixture, spoon mixture on one long side of the dough. Drizzle on 3 Tbsp. melted butter. Roll up like a jelly roll. Tuck in ends. Place in one of the prepared pans. Brush top with cream mixture. Cut a few slits over top. Set aside. Repeat with remaining dough. Bake in 400 degree oven for 10 minutes then reduce to 350 degrees for about 45 minutes more.