Preheat your oven to 400 degrees F. Unfold one sheet of puff pastry and cut it into six rectangles. Place on a parchment-lined baking sheet, spacing ½ inch apart. Repeat with the second sheet.

Mix strawberry jam, cornstarch, and lemon juice in a bowl. Spoon onto the center of each rectangle, leaving a ½-inch border.

Whisk the egg with 1 tablespoon of cream and brush onto the borders of each rectangle.

Prick the reserved pastry rectangles with a fork and place them over the filled rectangles. Press and crimp the edges to seal. Brush with remaining egg wash and sprinkle with coarse sugar.

Bake for 18 to 20 minutes until puffed and golden, rotating halfway for even browning. Cool on the pan for about 30 minutes.

Whisk powdered sugar, vanilla, salt, and remaining cream for the glaze. Drizzle over cooled strudels.