In a medium bowl, mix together the almond flour, sugar, and salt. Pour in the melted butter and stir until well blended.
Place the crust mixture in a 10-inch-wide x 1-inch-deep tart pan sprayed with cooking spray. Press and tamp the crust into the bottom and up the sides of the pan using a small smooth-bottomed cup.
Bake for 8 minutes or until lightly browned. Remove from the oven and cool completely, about 30 minutes.
Filling
In a mixing bowl, add the condensed milk and Tang. Stir until well mixed, and the Tang dissolves. Add the sour cream and stir. Then add the Cool Whip and fold in until well mixed.
Pour mixture into the cooled crust. Refrigerate until cold and serve chilled. Garnish with orange slices.
Notes
Chilling the Crust
If in a hurry, cool the cooked crust for a few minutes and then place it on a potholder in the freezer for 10 or 15 minutes.
Freezing
This tart can also be served frozen. Thaw for a few minutes before serving.
Sources
Orange Tang powdered drink mix can be found on Amazon and other online retailers.