In a bowl, combine the apples, sugar, cinnamon, nutmeg, raisins (if using), and lemon juice. Toss until everything is coated evenly.
Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper.
Place one sheet of filo dough on a clean, dry surface, and brush lightly with melted butter. Place another sheet on top, brush with butter, and repeat until you have a stack of 4 buttered sheets.
Sprinkle the toasted breadcrumbs or crushed graham crackers over the filo, leaving a 2-inch border on all sides. This will help absorb any excess moisture from the apples.
Spoon the apple filling evenly along one side of the filo stack, about 2 inches from the edge.
Fold the sides of the filo over the filling, then carefully roll it up tightly like a log. Place the strudel seam-side down on the prepared baking sheet and brush the top with a little more melted butter.
I Made two strudels from this amount of ingredients.
Bake for 30-35 minutes, until the filo is golden brown and crisp.
Let the strudel cool slightly, then dust with powdered sugar before slicing.
