Crust:

1. Preheat oven to 350 degrees. Line an 8×8 inch pan with parchment paper or aluminum foil or spray lightly with cooking spray.
2. In a medium size bowl, combine flour, brown sugar, and melted butter and mix together until incorporated. Press down evenly into prepared pan and and bake for 12 minutes or until lightly brown.

Coconut lime layer:

1. In a medium sized bowl, add egg yolks, sweetened condensed milk. lime juice, and zest.  Whisk together until smooth then stir in white chocolate chips. Pour over crust and sprinkle with coconut  Bake for 15 to 18 minutes or until set. Sprinkle with toasted coconut if desired.
2. Cool completely and refrigerate for an hour or two. For easy cutting, life out of pan holding sides of the parchment paper or foil. Store in refrigerator.