To a blender, add frozen mango and pineapple juice. Run on high until smooth, it will be thick and spoonable but ensure there are no chunks.
In the bottom of each glass, squeeze half a lime (about ½ tbsp), then add 1 tablespoon chamoy sauce and 1 teaspoon tajin. Stir to blend well.
Fill each glass about halfway with frozen mango mixture, then a layer of chamoy sauce (another tablespoon), then the remaining mango mixture.
Notes
Shaken/Stirred: This is a layered beverage, the layers of chamoy in the middle and on top creates the traditional sweet-spicy flavor bursts throughout.
Glass: Serve in a tall glass so you can prominently see the layers.
Garnishes: Traditionally, it is served with a tamarind candy straw, but a simple Tajin rimmed glass is classic, or add a little freshness with lime wedges or round and sprig of mint.
Seasoning Balance: Start with less Tajín and adjust depending on how spicy you like your drinks.
Cold Ingredients: Using frozen mango instead of ice keeps the flavor concentrated and prevents dilution.
Best Texture: Blend until completely smooth so the frozen mango mixture has a creamy slushy consistency.