Meanwhile, form pie crust dough in a regular-sized pie pan and poke the sides and bottom with a fork. Place the pie crust in the refrigerator until needed.
Once the yams are cool enough to handle, cut off ends, which tend to be stringy, and slice yams in half.
Scoop out the pulp and add to a mixing bowl.
Beat on medium speed for a few minutes. Stop occasionally to remove any stringy fibers that collect on the beaters.
Add eggs, yogurt, vanilla, butter, and half-n-half, and mix on medium until fully incorporated. Scrape the sides of the bowl with a spatula as necessary.
Add brown sugar, flour, salt, and the remaining spices. Mix on medium until all the ingredients are combined. Continue to remove the stringy fibers as they form on the beaters.
Pour mixture into the formed pie crust and bake, uncovered, for an hour or until the center of the pie is set. You can test for doneness by inserting a knife into the center of the pie. If the pie is done, the knife should come out relatively clean.
Cool to room temperature before storing in the fridge. Serve with whipped cream or cool whip, if desired.