Step 1

1 Position an oven rack in the lower third of the oven; preheat to 350 degrees

Step 2

2 Line the bottom of a 9-inch springform pan with parchment paper, then grease the pan with cooking oil spray

Step 3

3 Combine the almonds, chocolate, 1/2 cup of the granulated sugar and the salt in a food processor; pulse until the almonds and chocolate look very finely chopped but not completely pulverized

Step 4

4 Combine the egg whites and cream of tartar in the clean, dry bowl of a stand mixer or handheld electric mixer; beat on medium speed until soft, moist peaks are formed when the beaters are lifted

Step 5

5 Gradually add the remaining 1/2 cup of granulated sugar, continuing to beat until the egg whites are stiff but not dry

Step 6

6 Add one-third of the nut mixture to the egg whites; use a large flexible spatula to fold it in by hand until nearly incorporated

Step 7

7 Fold in half of the remaining nuts, then fold in the rest

Step 8

8 Scrape the batter into the pan, spreading it evenly

Step 9

9 Bake (lower rack) for 25 to 30 minutes, until the torte rises and is golden brown on top and a toothpick inserted in the center of the cake emerges free of batter, other than a little melted chocolate

Step 10

10 Transfer to a wire rack to cool

Step 11

11 Serve at room temperature, dusted with confectioners' sugar