Make the topping: Combine 1 cup sugar, the lime zest, lime juice and 1 cup water in a small saucepan and bring to a boil, stirring to dissolve the sugar. Add the jalapeno slices, reduce the heat to medium and cook, stirring occasionally, until tender, about 10 minutes. Remove from the heat and let the jalapeno cool in the syrup, at least 1 hour.
Strain the jalapeno; reserve the syrup. Spread 1/2 cup sugar on a small plate. One at a time, toss half of the jalapeno slices in the sugar until lightly coated. (Set the remaining jalapeno slices aside.) Let the sugared jalapeno slices dry until hardened, at least 4 hours or overnight.
Make the crust: Preheat the oven to 350 degrees F. Pulse the remaining 1/4 cup sugar and 2 unsugared jalapeno slices in a food processor until ground. Add the cookie crumbs and butter and pulse to combine. Press into the bottom and up the side of a 9-inch pie plate. Bake until golden brown, 12 to 14 minutes. Transfer to a rack to cool completely.
Make the filling: Combine the orange juice and gelatin in a small microwave-safe bowl and set aside to soften, about 5 minutes. Puree the mangoes in a blender until smooth, about 1 minute. Add the reserved jalapeno syrup, the vanilla and 1 teaspoon salt and puree until smooth. Microwave the juice-gelatin mixture until just hot and liquefied, about 30 seconds. Stir to make sure the gelatin is dissolved, then add to the mango mixture in the blender and puree until smooth. Strain the mango mixture through a fine-mesh sieve into a bowl, then pour into the cooled crust. Press a sheet of plastic wrap onto the surface to prevent a skin from forming. Refrigerate until set, at least 6 hours or overnight.
Make the meringue: Combine the sugar, cornstarch, cream of tartar, egg whites and the remaining 1/2 teaspoon salt in a large heatproof bowl. Set the bowl over a medium saucepan of simmering water (do not let the bowl touch the water) and cook, stirring constantly, until the sugar dissolves and the egg whites are hot to the touch, 3 to 4 minutes. Remove the bowl from the water and beat with a mixer on medium-high speed until the mixture is light and fluffy and stiff peaks just form, about 2 minutes.
Finely chop the remaining unsugared jalapeno slices and combine with a large spoonful of the meringue in a small bowl. Add to the remaining meringue and whisk to combine. Transfer to a piping bag fitted with a large open star tip. Pipe the meringue on top of the pie to make a dome with spiky peaks. Lightly brown the meringue with a kitchen torch and top with the reserved sugared jalapeno slices.