Preheat your oven to 350°F (175°C). Grease and line an 8-inch round cake pan with parchment paper.

In a microwave-safe bowl, melt the chocolate chips in 30-second intervals, stirring in between until smooth. Allow to cool slightly.

In a large mixing bowl, beat the egg yolks with granulated sugar and 1 teaspoon of vanilla extract until the mixture is pale and thick.

Gradually fold the melted chocolate into the egg yolk mixture until well combined.

In a separate bowl, beat the egg whites with salt until stiff peaks form. Gently fold the egg whites into the chocolate mixture in three additions, being careful not to deflate the mixture.

Pour the batter into the prepared cake pan and smooth the top. Bake for 25-30 minutes or until the cake is set but still slightly soft in the center. Remove from the oven and let it cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

While the cake is cooling, whip the heavy cream with powdered sugar and 1/2 teaspoon of vanilla extract until soft peaks form.

Once the cake is completely cool, spread the whipped cream over the top of the cake. Garnish with chocolate shavings or a dusting of cocoa powder if desired.

Chill the cake in the refrigerator for at least 1 hour before serving to allow the flavors to meld.