Line 8x8 inch pan with foil and spray with cooking spray. Mix crumbs and butter and spread on bottom of pan, patting down lightly. Bake 10 min. in a 350 degrees oven.
Beat egg yolks in medium bowl with electric mixer. Add sweetened condenced milk and beat together. Drizzle in lime zest, mixing and then add lime juice and beat thoroughly.
Pour into pan over crust. Bake 15 minutes at 350 degrees on middle rack. Cool and refrigerate for several hours before lifting out by foil and cutting into 16 squares. Embellish each square with small lime pieces.