Toss apples, granulated sugar, lemon zest and juice, cinnamon, ginger, and pinch salt together in large bowl.

Cover and microwave until apples are warm to touch, 60 to 75 seconds, stirring once halfway through microwaving.

Let apples stand, covered, for 5 minutes.

Transfer apples to colander set in second large bowl and let drain, reserving liquid.

Return apples to bowl; stir in raisins and panko.

Adjust oven rack to upper-middle position and heat oven to 375 degrees.

Spray rimmed baking sheet with vegetable oil spray.

Stir pinch salt into melted butter.

Place 16 ½ by 12-inch sheet of parchment paper on counter with long side parallel to edge of counter.

Place 1 phyllo sheet on parchment with long side parallel to edge of counter.

Place confectioners’ sugar in fine-mesh strainer (rest strainer in bowl to prevent making mess).

Lightly brush sheet with melted butter and dust sparingly with confectioners’ sugar.

Repeat with 6 more phyllo sheets, melted butter, and confectioners’ sugar, stacking sheets one on top of other as you go.

Arrange apple mixture in 2 ½ by 10-inch rectangle 2 inches from bottom of phyllo and about 2 inches from each side.

Using parchment, fold sides of phyllo over filling, then fold bottom edge of phyllo over filling.

Brush folded portions of phyllo with reserved apple liquid.

Fold top edge over filling, making sure top and bottom edges overlap by about 1 inch.

(If they do not overlap, unfold, rearrange filling into slightly narrower strip, and refold.)

Press firmly to seal.

Using thin metal spatula, transfer strudel to prepared sheet.

Lightly brush top and sides of strudel with remaining apple liquid.

Bake until golden brown, 25 to 30 minutes, rotating sheet halfway through baking.

Using thin metal spatula, immediately transfer strudel to cutting board.

Let cool for 3 minutes.

Slice strudel into quarters and let cool for at least 20 minutes.

Serve warm or at room temperature, dusting with extra confectioners’ sugar before serving.