Make the Tropical Base:
In a blender, combine pineapple chunks, coconut milk, whole milk, cream of coconut, sweetener, and ice. Blend until smooth and creamy.
Assemble the Frappuccino:
Pour the blended pineapple-coconut mixture into two tall clear glasses, filling each about 3/4 full.
Create the Sunset Swirl:
Slowly pour the cherry juice or grenadine along the inside edge of the glass. It will sink and create a beautiful red gradient at the bottom.
Top It Off:
Add a generous swirl of whipped cream. Garnish with a maraschino cherry and a small pineapple wedge on the rim, if desired.
Serve Immediately:
Insert a wide straw and enjoy the creamy tropical layers and vibrant colors.