Blend the Base: In a blender, combine frozen mango chunks, sweetened condensed milk, lime juice, and vanilla extract. Blend until super smooth and thick. Scrape down sides as needed.
Whip It Good: In a separate, large, chilled bowl, use an electric mixer to whip the very cold heavy cream until stiff peaks form.
Gently Does It: Pour the smooth mango mixture into the whipped cream. Gently fold together with a spatula until just combined. Avoid overmixing; streaks are okay.
Spice It Up: Gently fold in 1 tablespoon chili lime seasoning and the desired amount of cayenne pepper (start with 1/8 tsp). Taste carefully if desired.
Layer and Swirl (Optional): Pour half the mixture into a loaf pan or freezer-safe container. Sprinkle with another 1-2 tsp chili lime seasoning. Gently top with remaining mixture. Swirl gently with a knife if desired.
Freeze Time: Cover tightly (press plastic wrap directly onto the surface, then add lid/foil). Freeze for at least 6 hours, or overnight, until firm.
Serve with Sass: Let ice cream sit at room temperature for 5-10 minutes before scooping. Garnish with extra chili lime seasoning if desired.