Place the finely diced apples into a medium bowl, drizzle with the fresh lemon juice, and toss thoroughly to coat. The citric acid prevents the apple cells from oxidizing and turning brown while you prepare the remaining steps.

In a medium, heavy-bottomed saucepan, combine the light brown sugar, 1 teaspoon of the ground cinnamon, and the cornstarch. Whisk the dry baseline together to break up any stubborn sugar clumps.

Pour the 2 tablespoons of water and the vanilla extract into the saucepan, stirring until the sugar starts to dissolve into a thick paste. Drop the diced apples directly into the pan and stir until every piece is coated.

Place the saucepan over medium heat. Cook the mixture for 6 to 8 minutes, stirring frequently with a silicone spatula, until the apples soften slightly and the liquid bubbles and thickens into a heavy, clear caramel glaze matrix. Remove from the heat and let the filling cool down completely to room temperature.

Preheat your oven to 400°F (204°C). Line a large, flat baking sheet with premium parchment paper.

In a small bowl, whisk together the granulated white sugar and the ½ teaspoon of ground cinnamon to create your topping mix. Set it aside along with your melted butter.

Layout one egg roll wrapper flat onto a clean cutting board, positioning it like a diamond with one corner pointing directly at you. Keep the remaining wrappers covered with a damp paper towel so they do not dry out and split.

Spoon roughly 2 tablespoons of the cooled apple filling baseline across the center of the wrapper, shaping it into a small horizontal log.

Lift the bottom corner pointing toward you and fold it tightly up and over the apple filling. Fold the left and right corners inward toward the center, creating an envelope shape.

Lightly dip your finger into a small cup of water and brush it along the remaining top edges of the wrapper. Roll the egg roll upward tightly away from you, pressing firmly along the wet border to seal the seam completely. Arrange the roll seam-side down on the prepared baking sheet. Repeat the process for the remaining rolls.

Using a pastry brush, coat the entire surface of each egg roll generously with the melted butter. Immediately scatter the cinnamon-sugar topping mixture uniformly over the wet butter.

Place the sheet pan on the middle rack of the oven and bake at 400°F for 12 to 15 minutes. Turn the egg rolls over halfway through the baking cycle to guarantee an even crunch. They are finished the exact moment the wrapper surfaces turn puffy, blistered, and deep golden brown.

Remove from the oven and let them rest flat on a wire cooling rack for 5 minutes. The interior fruit filling stays exceptionally hot, so this cooling window allows the syrup to settle safely. Serve warm alongside a small bowl of rich caramel sauce for dipping.