Chocolate Pavé

1. Preheat Oven and Prepare Baking Dish

Preheat your oven to 350°F. Butter a 9- by 13-inch baking dish, line it with parchment paper, butter again, and then dust with flour or cocoa powder. Shake out any excess.

2. Melt Chocolates and Butter

Combine the unsweetened chocolate, semisweet chocolate, and butter in a medium heat-proof bowl. Set this bowl over simmering water, stirring occasionally until the mixture is smooth and shiny. Allow it to cool slightly.

3. Whisk Egg Yolks with Sugar

While the chocolate mixture cools, whisk the egg yolks with ½ cup of sugar for about 10 minutes, until the mixture is thick and forms a ribbon when lifted.

4. Combine Egg Yolk Mixture with Chocolate

Fold the yolk mixture into the melted chocolate until well combined.

5. Whisk Egg Whites with Sugar and Salt

In a separate clean bowl, whisk the egg whites with the salt. Gradually add the remaining ½ cup of sugar, continuing to whisk until the mixture looks glossy and holds soft peaks.

6. Fold Egg Whites into Chocolate Mixture

Gently fold the egg whites into the chocolate mixture in three parts, ensuring you do this slowly to avoid deflating the mixture. Stop folding as soon as there are no visible streaks of white.

7. Bake the Torte

Pour the batter into the prepared baking dish and smooth the top. Bake for 35 to 40 minutes, until the sides are set and the center is slightly soft. Let the cake cool completely in the dish.

8. Cool and Serve

Once cool, invert the cake onto a baking sheet, remove the parchment paper, and then invert again onto a serving platter. Dust with sifted powdered sugar before serving.