Tangerine Chiffon Pie

Preheat the oven to 350°F. Boil the tangerine-orange juice in a small saucepan over medium-high heat until it has reduced to about 1 cup, 18 to 20 minutes. Remove from heat; set aside.

Pulse cookies, 1 tablespoon lemon zest, and 1/4 cup sugar in a food processor until thoroughly combined. With processor running, add melted butter; process until combined. Press cookie mixture evenly into bottom, up sides, and onto rim of a 10-inch pie plate. Bake until golden brown, about 15 minutes. Transfer to a wire rack to cool completely.

Put lemon juice into a small bowl. Sprinkle with gelatin. Let soften 10 minutes. Meanwhile, whisk together yolks, 1/2 cup sugar, the juice reduction, and the remaining 2 teaspoons zest in a medium saucepan. Cook over medium-low heat, stirring constantly, until thickened, about 10 minutes (do not let boil). Remove from heat. Add gelatin mixture, and whisk until gelatin has dissolved completely.