Preheat oven to 350°F. Line bottom and sides of a 9-inch springform pan with parchment paper, allowing 1 to 2 inches excess to hang over sides.

Working in batches, process pecans in a food processor until finely ground like coarse sand, 15 to 20 seconds. (Do not over process to a paste.) Set pecans aside.

Beat egg whites and salt in bowl of a stand mixer fitted with a whisk attachment on medium speed until frothy and opaque, 1 to 2 minutes. With mixer running on medium speed, add powdered sugar, gradually increasing speed to high, and beat until stiff, glossy peaks form, about 5 minutes.

Beat egg yolks in a large bowl with an electric mixer on high speed until thick, fluffy, and pale yellow, 4 to 5 minutes. Fold one-third of the beaten whites into yolks until just combined; fold in remaining beaten whites until just combined. Fold in ground pecans until just combined. Pour batter into prepared pan. 

Bake in preheated oven until a wooden pick inserted into center comes out clean, 30 to 35 minutes. Transfer cake to a wire rack, and let cool completely, about 1 hour. Run a knife around outer edge of pan to loosen from sides of pan; remove sides of pan. Store at room temperature in an airtight container or tightly wrapped in plastic wrap up to 2 days or in the refrigerator up to 4 days.