The rich color of sweet potatoes help give them added nutrition, making this dish both a sweet and healthy dessert.
Boil sweet potatoes in their skins until soft. Cool, remove skins and put through a food mill.
Beat butter and 1 cup sugar, then add 4 egg yolks and beat until creamy. Add vanilla and cinnamon and continue beating, then add orange zest, juice and half-and-half. Add sweet potato puree last, then ladle mixture into an unbaked, 9-inch pie shell.
Bake at 400 degrees Fahrenheit for 10 minutes. Reduce heat to 350 degrees and bake until done (pie will spring back to the touch, be domed in the center, and a toothpick inserted in the center will come out clean).
To make Meringue
Whip 4 egg whites on high speed with cream of tartar and 1/4 cup sugar until stiff peaks form. Place meringue on the cooked pie and bake at 400 for about 10 minutes, until nicely browned.