Preheat the oven to 140°C (285°F). Line a baking sheet with parchment paper.

Whisk the egg whites with a pinch of salt and citric acid until you get soft peaks. Gradually add the sugar while continuing to beat, until the egg whites form stiff peaks and the mixture becomes glossy. This may take a few minutes.

Add the cornstarch and continue to whisk for another minute to ensure it's fully incorporated.

Spread the meringue mixture evenly onto the prepared baking sheet, forming a rectangle or a shape of your choice. If desired, sprinkle almond flakes over the top for added texture.

Bake the meringue for 30–35 minutes at 140°C (285°F). If using a gas oven, reduce the temperature to 100°C (212°F) to avoid over-drying. The meringue should be crisp on the outside and slightly soft inside.

Cool the meringue: Once done, remove from the oven and let it cool completely on a wire rack. Once cooled, carefully flip it over, remove the parchment paper, and allow it to cool further.

Prepare the mandarins: Peel the mandarins, then blend them briefly to release the juice. Strain the juice through a fine mesh sieve to remove the pulp.

Cook the curd: In a small saucepan, combine the mandarin juice, egg yolks, cornstarch, and sugar. Whisk everything together, then heat over medium heat, stirring constantly until it thickens (this may take 5–10 minutes). Once thickened, remove from heat and let the curd cool to room temperature.

Whip the cream: In a chilled mixing bowl, beat the cold heavy cream until it begins to thicken. Gradually add the powdered sugar and continue whipping until soft peaks form.

Combine with cream cheese: In another bowl, beat the cream cheese until smooth and fluffy. Gently fold in the whipped cream, mixing until the filling is smooth and well combined.

Spread the mandarin curd: Once the meringue has cooled, spread a thin, even layer of the mandarin curd over the surface, leaving a small border around the edges.

Add the cream filling: Using a pastry bag or spoon, spread the whipped cream mixture evenly on top of the curd layer.

Roll it up: Carefully roll the meringue into a tight log, starting from one edge. Be gentle to avoid cracking the meringue. Once rolled, refrigerate the roll for at least 30 minutes to set.

Decorate: Once chilled, decorate the roll with optional garnishes like fresh mandarin slices, berries, or a dusting of powdered sugar.

Slice and serve: Slice the roll into portions, and enjoy this delightful dessert with its perfect balance of sweet, creamy, and citrusy flavors!