Preheat the oven to 350 degrees and line an 8×8 inch baking dish with parchment paper.
Add all the shortbread ingredients to a food processor and pulse until well combined with just a few lumps remaining.
Press the mixture in an even layer in the baking dish (I like to use a large glass to get it packed it tightly) and bake for 20 minutes until golden brown. Remove and set aside to cool.
While the shortbread is baking, prepare the coconut layer by adding all ingredients to a blender (or food processor) and puree until completely blended and creamy.
Spread the coconut layer over the shortbread layer and place in the freezer for 20 minutes until slightly firm.
While the first two layers are chilling, make the mango puree by first combining the arrowroot powder and water in a small bowl then adding to a blender with the mango chunks and pureeing until smooth.
Pour the mango puree over top of the first two layers and place back in the freezer until completely frozen – this should take about 2 hours. Cut the bars into even pieces and store in the fridge or freezer.
To serve, let the bars thaw for about 20 minutes and enjoy!