Add the heavy cream and lime zest to a large saucepan and heat over medium. Stir only until the mixture comes to a gentle boil. Remove from heat and let it sit for 30 minutes. This will allow the lime flavor to infuse well into the mixture.
In a microwavable bowl, add the chopped white chocolate, lime juice, and unsalted butter. Do not stir, just set aside.
After 30 minutes has passed, place the saucepan over medium heat again until just simmering. Remove from heat. Place a mesh sieve over the white chocolate mixture in bowl, and pour cream over to remove lime zest.
Gently begin stirring the white chocolate mixture in one direction. Do not over stir. Once the mixture has completely melted and is smooth, add a piece of plastic wrap to the top of the ganache. Let it sit at room temperature for 1 hour and then transfer to the fridge for at least 6 hours. Overnight will work as well.
After refrigerating the ganache, the filling will be soft enough to roll into balls. Line two baking sheets with parchment paper. Set aside.
Take 1 teaspoon of ganache filling, roll between your hands into a ball. Place each ball on the prepared baking sheet. Repeat with the remaining ganache, cleaning hands in between. Place baking sheets in the fridge to chill while making coconut coating.