Step 1

Preheat oven to 350°F.  Pulse cookies in a food processor until finely ground, about 10 pulses. Add butter and ¼ teaspoon of the kosher salt; pulse until mixture starts to clump and sticks together when pinched with fingers, about 10 pulses. Press mixture evenly into bottom and 1 ½ inches up the sides of a 9-inch springform pan. Bake in preheated oven until crust is toasted and deep golden brown, 8 to 10 minutes. Remove from oven. Place on a wire rack, and let cool 30 minutes.

Step 2

Beat whipping cream with a stand mixer fitted with a whisk attachment on medium speed until frothy, about 30 seconds. Increase mixer speed to medium-high; beat until peaks are almost stiff but still soft, 1 to 2 minutes. Transfer whipped cream to a large bowl. Set aside.

Step 3

Rinse mixer bowl, and wipe dry; remove whisk attachment from stand mixer, and fit with paddle attachment. Add cream cheese and granulated sugar to mixer bowl; beat with paddle attachment on medium-high speed until completely smooth and creamy, 1 to 2 minutes, stopping to scrape down sides as needed. Add powdered sugar; beat on low speed until combined, about 30 seconds. Add sour cream, vanilla, ¼ cup of the dulce de leche, and remaining ⅛ teaspoon kosher salt; beat until combined, about 30 seconds. Using a rubber spatula, carefully fold whipped cream into cream cheese mixture until fluffy and no whipped cream streaks remain.

Step 4

Pour half of the cream cheese mixture into cooled crust. Drizzle with 2 tablespoons of the dulce de leche; drag the tip of a knife or a wooden pick through caramel to create swirl patterns. Spread remaining cream cheese mixture over dulce de leche. Top with remaining 2 tablespoons dulce de leche; repeat swirl patterns using tip of knife. Cover cake with plastic wrap. Refrigerate until set, at least 4 hours or up to 12 hours.

Step 5

Run a sharp paring knife around edges of crust to loosen from springform pan. Remove sides of springform pan. Slice cake. Sprinkle with sea salt, and serve cold.