Step 1: Prepare the Apple Filling

1. In a skillet over medium heat, melt butter and add sliced apples.
2. Stir in brown sugar, cinnamon, nutmeg, vanilla extract, and lemon juice.
3. Cook for 5-7 minutes, stirring occasionally, until apples soften.
4. Mix cornstarch with 1 tbsp water and add to the apples, stirring until thickened.
5. Remove from heat and let cool.

Step 2: Assemble the Puff Pastry Rolls

1. Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. Roll out the puff pastry on a lightly floured surface.
3. Sprinkle a thin layer of granulated sugar over the pastry.
4. Spread the cooled apple mixture evenly over the pastry, leaving a ½-inch border.
5. Roll the pastry tightly from the bottom, forming a log.
6. Slice into 2-inch pieces and place them on the baking sheet, cut side up.
7. Brush tops with egg wash and sprinkle with sugar and chopped nuts.

Step 3: Bake & Serve

1. Bake for 20-25 minutes, or until golden brown and flaky.
2. Let cool slightly before serving.
3. Enjoy warm, optionally drizzled with caramel sauce or served with vanilla ice cream.