MAKE CRUST: Adjust over rack to middle position and heat oven to 350 degrees. Process graham crackers and sugar in food processor to fine crumbs. Add butter and 2 tablespoons cream cheese and pulse until combined. Press crumbs into bottom and sides of 9 inch pie plate. Bake until lightly browned and set, 12 to 14 minutes. Cool completely.
MAKE FILLING: Combine 3 tablespoons lime juice and gelatin in small bowl and let sit until gelatin softens, about five minutes. Microwave until mixture is bubbling around edges and gelatin dissolves, about 30 seconds. Wipe out food processor and process condensed milk, yogurt, and remaining cream cheese until smooth, about 1 minute. With machine running, pour in gelatin mixture, remaining lime juice, zest, and vanilla and process until thoroughly combined.
CHILL PIE: Scrape mixture into cooled pie shell and smooth top. Cover with plastic wrap and refrigerate until firm, at least 3 hours or up to 2 days. Serve.