Step 1

Whisk together cracker crumbs, sugar, and salt. Stir in butter until mixture resembles wet sand and holds together when squeezed. Press evenly into the bottom of a 9-inch springform pan. Freeze until firm, 15 minutes.

Step 2

Meanwhile, in the bowl of an electric mixer fitted with the paddle attachment, beat cream cheese and condensed milk on medium-high speed until fluffy, about 5 minutes. Add lime juice, zest, and vanilla. Beat 1 minute more.

Step 3

In a separate bowl, whip cream to stiff peaks. Gently fold into cream-cheese mixture. Pour over chilled crust; smooth top with an offset spatula. Cover with plastic and refrigerate at least 12 hours and up to 3 days.

Step 4

Run a knife along cake's edge before releasing sides of pan, then under bottom to loosen. Serve, garnished with lime rounds.