Make sure phyllo dough is thawed; if frozen, let sit at room temperature for about an hour. Prepare a baking sheet with parchment paper. Make sure parchment paper covers the baking sheet because when the strudel bakes, the juices from the filling will ooze out and are very sticky. Preheat oven to 425 degrees and position rack in the middle position. Peel and core apples, slice into 1/4" pieces. In a medium bowl, add apple pieces, raisins, apple cider vinegar, brown sugar, sugar, cinnamon, and pecans and stir to coat.

Melt butter in microwave or in a small pan and keep handy. Unroll phyllo dough and keep it covered with plastic and a VERY lightly dampened towel. The sheets are very fragile and will dry out quickly if left out. Place one phyllo sheet on prepared baking sheet and lightly brush with melted butter. Place another sheet on top and again lightly brush with melted butter. Repeat this process until you have 8 layers of phyllo. Make sure to keep the unused phyllo covered: once they are brushed with butter, you do not need to cover them.

Pile apple filling along the bottom (long) edge of the phyllo layers, about 1/2" up from the bottom. Make sure to disperse the raisins and pecans amongst the apples so every bite is delicious.

Roll the strudel up, trying to keep it as tight as possible. Make sure to put the seam on the bottom to prevent unrolling. Brush top and sides with butter and put in oven. Bake approximately 23-25 minutes, until it is deep golden brown.

While the strudel is baking, in a small bowl, combine 1/2 cup powdered sugar with 1 Tbsp. warm tap water and mix until sugar dissolves. If consistency is too thick, add additional water .5 tsp. at a time and stir. Set aside to use as a drizzle on top of the strudel.

Let strudel cool down (about 10 minutes) before drizzling icing on top so the icing does not just melt off. Use a spoon to drizzle the glaze topping over strudel. If possible, use a serrated knife to slice. It will be very flakey, so be gentle when slicing. In general, strudel is flaky on the top, soggy on the bottom. If that matches what you've got, you'e made a strudel!