Preheat oven to 350˚F. Spray 6 - 4 ½-inch removable bottom tart pans with baking spray. Rub with a paper towel to evenly distribute spray. Line bottoms with parchment paper, if desired.

Process graham crackers till finely ground. Add butter and sugar and process till combined. Add pecans and pulse 6-10 times or until coarsely ground. Add coconut and pulse 3-4 times, just till incorporated.

Divide between 6 tart pans with removable bottoms. About ⅓ generous cup per pan. Press graham cracker mixture firmly up sides and into bottom of pans. Place tart pans on a sheet pan. Bake for 10 minutes. Remove from oven and cool completely.

For the filling - in a medium heatproof bowl, whisk together the egg yolks and sugar until smooth and combined. Add lime juice and stir. Place bowl over a pan of simmering water and cook for 4-5 minutes, stirring frequently until mixture thickens. Remove from heat and add condensed milk, Greek yogurt and all but 1 teaspoon of the lime zest.

Divide evenly between the baked crusts and sprinkle with the reserved lime zest. Freeze, uncovered for at least 2 hours. If not serving after this initial freezing, cover tightly with foil. Will keep for several weeks in the freezer. Remove from freezer 10-20 minutes before serving. Add a dollop of freshly whipped cream, if desired.