Step 1: Create the Blueberry Puree Base
In a blender, combine the 1 cup of blueberries, ½ cup of blueberry juice, 2 tablespoons of lime juice, and 1-2 tablespoons of your chosen sweetener. Blend on high speed until the mixture is completely smooth.

Step 2: Strain for a Silky Texture
For the most elegant, pulp-free texture, strain the blueberry puree through a fine-mesh sieve into a pitcher or bowl. Use a spatula to press down on the solids, extracting all the beautiful liquid. Discard the leftover pulp. This step is optional but highly recommended for a crystal-clear, professional-looking drink.

Step 3: Prepare the Coconut Cream Layer
In a separate bowl or measuring cup, whisk together the 1 cup of coconut milk, ¼ cup of coconut water, and the optional 1 tablespoon of sweetener and ½ teaspoon of vanilla extract. Whisk until the mixture is smooth and homogenous. If your coconut milk has separated in the can, be sure to whisk it vigorously or shake it in a sealed jar before measuring.

Step 4: Assemble the Cooler with Care
Fill tall glasses about halfway with fresh ice cubes. For the signature layered look, you must pour the denser liquid first. Slowly and gently pour the blueberry puree over the ice, filling each glass about two-thirds of the way full.

Step 5: The Layering Technique
This is the key to the beautiful ombre effect. Take a spoon and turn it upside down, placing the back of the spoon just above the surface of the blueberry layer. Slowly and carefully pour the coconut mixture over the back of the spoon. The spoon will disperse the liquid, allowing the lighter coconut layer to float gently on top of the denser blueberry layer, creating a stunning separation.

Step 6: Add the Final Touches
If you desire a bit of fizz, top each glass with a small splash of sparkling water or club soda. Be gentle to avoid mixing the layers.

Step 7: Garnish and Serve Immediately
Skewer a few fresh blueberries and a small lime slice on a cocktail pick or toothpick and rest it on the rim of the glass. Add a sprig of fresh mint and a sprinkle of toasted coconut flakes for a final touch of elegance. Serve immediately with a straw, and encourage your guests to stir the layers together before drinking to enjoy the full flavor harmony.