Preheat your oven to 150°C (300°F) and line two baking trays with parchment paper.

In a large mixing bowl, beat egg whites and salt until soft peaks form. Gradually add granulated sugar and whip until stiff peaks form, about 5–7 minutes.

Sift powdered sugar, finely ground almonds, and cornstarch into a separate bowl. Gently fold this mixture into the meringue until smooth.

Transfer the meringue mixture into a piping bag and pipe 8–10 cm discs onto the prepared trays, smoothing the tops with a spatula.

Bake the meringues for 40–45 minutes until crisp. Allow them to cool in the turned-off oven with the door ajar.

While meringues cool, whip heavy cream, powdered sugar, and vanilla extract until soft peaks form, then gently fold in toasted sliced almonds.

Spread or pipe the almond cream on half of the meringue discs and sandwich with remaining discs.

Dust the assembled cookies with powdered sugar and sprinkle with additional sliced almonds if desired.