In a medium bowl, stir together the coconut milk, oats and yogurt. Cover with plastic wrap and store in the refrigerator overnight or for 8 hours.
Remove the plastic wrap and stir the oats to combine. (If the mixture is thicker than you prefer, add 2 tablespoons of coconut milk or regular milk until the desired consistency.)
Spoon about ¼ cup of the oats into the bottom of four 4 ounce jars or resealable containers. Top the oats with a handful of blueberries and top with another ¼ cup of the oats. Add a few more blueberries on top of the final layer of oats and sprinkle with the toasted coconut flakes.
Seal each jar with a lid or plastic wrap if making ahead and store in the refrigerator for up to 3 days, or serve immediately.
Notes
Overnight oats can be made up to 4 days in advance and stored in the refrigerator in an airtight container.