Preheat the oven to 350°F (180°C). Place all the crust ingredients except the butter into the bowl of a food processor and pulse until mixed.
Melt the butter and pour it slowly into the food processorpulsing just until the crumbs are evenly moistened and begin to stick together. Press the mixture into the pie pan, extending the crust up the sides.
Bake the crust for 12 to 15 minutes or until lightly browned. Allow the crust to cool while you prepare the filling.
Soak the gelatin sheets in ice water, then squeeze them dry. Warm half of the cream with the condensed milk in a saucepan, then add the gelatin and whisk thoroughly until just dissolved (you’ll want to purée it with a hand blender if you use powdered gelatin).
Remove the saucepan from the heat and add the remaining cream, salt, and sugar. Set the saucepan in a sink or bowl full of cold water and whisk the mixture until it reaches room temperature.
Pour the mixture into a blender, add the spruce tips, and purée for 30 seconds or so until well blendedthen strain through the finest strainer you have. Whisk the lime zest and juice into the mixture well, which will cause the filling to thicken, then pour it into the crust and refrigerate until set, a few hours.
