Add everything to a blender:
Combine dragon fruit, blueberries, milk, ice, yogurt, sweetener, and vanilla in a blender.
Blend until smooth:
Blend on high until the mixture is creamy and thick. Add a splash more milk if it’s too thick.
Add a swirl (optional):
Spoon a bit of dragon fruit or blueberry syrup around the inside of your cup for a layered, colorful effect.
Pour and top:
Pour the frappuccino into a glass. Add whipped cream and garnish with a few berries or extra purée if you like.
Serve immediately:
Add a straw, sip, and enjoy the fruity, tropical burst!