• Preheat the oven to 325°F and position a rack in the center. Lightly coat the bottom and sides of a 9-inch springform pan with nonstick cooking spray. Line the bottom with parchment paper and lightly spray the parchment.

Prepare the Cake Batter

• Add the unsalted butter and bittersweet chocolate chips to a microwave-safe bowl, and microwave at 50% power for 30 seconds at a time, giving everything a good stir between each round.
• Once the butter and chocolate are melted and smooth, stir in the vanilla extract.
Let the mixture cool until it's just slightly warm before moving on.
• Separate the eggs, placing the yolks in a large mixing bowl and the whites in a separate clean and dry mixing bowl.
• Add ½ cup of granulated sugar to the yolks. Using a stand mixer, beat on medium-high speed for 3 to 4 minutes, until the mixture is thick, pale yellow and creamy.
A hand mixer works too.
• Gradually add the slightly cooled chocolate mixture to the egg yolks, mixing on low speed until smooth and combined. Add the almond flour, Dutch-process cocoa powder and fine sea salt. Gently mix with a rubber spatula until evenly combined.
The batter will be thick.
• Using clean, dry beaters, beat the egg whites on medium speed until they start to foam. Increase the speed to medium-high and slowly add the remaining ½ cup granulated sugar. Keep beating until the egg whites look thick and glossy.
When you lift the beaters, the peaks should stand nearly upright, with just a slight bend at the tips.
• Add about one-third of the whipped egg whites to the chocolate batter and stir thoroughly with a rubber spatula to loosen the thick mixture.
• Add the remaining egg whites in two additions, gently folding from the bottom of the bowl upward until no large white streaks remain.
Avoid overmixing because that can make the cake dense.

Bake the Torta Caprese

• Transfer the batter into the prepared 9-inch springform pan and gently smooth the top with a spatula.
• Set the pan on a rimmed baking sheet and bake for 45 to 55 minutes, beginning to check it at 45 minutes.
The cake is done when a cake tester or toothpick inserted into the center comes out with a few moist crumbs attached, but no wet batter. The toothpick shouldn't come out completely clean.

Let It Cool

• Take the cake out of the oven and set the pan on a wire cooling rack. Let it cool for 20 minutes, then carefully run a thin knife around the edge and remove the springform ring.
• Leave the cake on the pan base for another 2 hours, or until completely cool, before carefully transferring it to a serving plate.
• Once the torta is completely cooled, dust the top with powdered sugar, then slice and serve.