In a high-speed blender, add the frozen pineapple chunks, pineapple juice, unsweetened coconut milk, and 1 cup of ice cubes.
Blend on high speed for 45-60 seconds, or until the mixture is completely smooth and creamy with no visible ice chunks.
Taste the refresher. If you prefer it sweeter, you can add 1-2 teaspoons of honey, agave, or simple syrup and blend for another 5 seconds.
Fill two clear glass cups with fresh ice cubes. Pour the blended Pineapple Coconut Refresher over the ice. Garnish with a pineapple slice, a sprig of mint, and a sprinkle of toasted coconut flakes if desired.