How to Make It
Preheat a grill to high (450°F to 500°F), or heat a grill pan over high. Grill pineapple ring, uncovered, until charred, about 2 minutes per side. Cut in half crosswise.
Rub lime wedge around rim of a rocks glass. Place Tajín Clásico seasoning in a shallow plate; dip rim of glass in seasoning to coat rim. Fill glass with ice. Muddle papaya-pineapple nectar, kosher salt, fresh lime juice, and half a grilled pineapple ring in a cocktail shaker; fill three-fourths full with ice. Add reposado tequila, simple syrup, and mango liqueur; cover and shake vigorously 30 seconds. Strain into prepared rocks glass. Garnish with mint and a wedge of the remaining grilled pineapple ring, and serve immediately.