Place about three quarters of the sweetened shredded coconut in a food processor and pulse just enough to break it down slightly. It should resemble coarse crumbs. Do not over-process because the mixture will become too fine and the fat in the coconut can cause it to clump up. Combine this coconut with the remaining of shredded coconut in a small bowl and set it aside. This will provide some texture contrast.

In a small saucepan over low heat, stir together chopped white chocolate, sweetened condensed milk, corn syrup, vanilla extract and salt until chocolate is completely melted and the mixture is smooth, about 5 minutes. Add coconut and stir it all together until well combined. Cover with plastic wrap and refrigerate mixture until rather firm, at least 2 hours.

Line two baking sheets with parchment paper and set one aside for later. Remove the coconut mixture from the refrigerator and use clean hands to shape tablespoons of this mixture into 1 to 1½-inch cylinders or logs. If the mixture is still a bit sticky, place it in the freezer for a few minutes. Resist the urge to add more coconut or icing sugar because it will dry out the filling and make it crumbly over time. Flatten each log slightly and place them on prepared baking sheet. Continue with remaining coconut mixture. Place baking sheet in the refrigerator until coconut candies are firm, about 30 minutes.

Place 6 oz of dark chocolate in a heatproof bowl set over a pot with ½-inch of barely simmering water. Stir constantly until almost completely melted (some small pieces of solid chocolate should remain). Remove bowl from over pot and stir until completely melted. Add remaining chocolate and stir until smooth and melted, placing bowl over hot water for a few seconds if necessary. Do not let the chocolate temperature rise above 90°F, or else it will lose its temper and won’t set up with a shiny finish and crisp snap.