Ingredients for Sweet Potato Fluff. Easy, Old-Fashioned Recipes & Traditional Skills. nutmeg ; 1 tbsp. Old-fashioned sweet potato pie brings back memories. This is my grandmother’s recipe for Sweet Potato Fluff, a real family favorite at Thanksgiving, Christmas, or anytime. I also pre-baked the sweet potatoes before blending them with the hand mixer. Next time I might try raising the oven temperature. I used purple sweet potatoes instead of the traditional yellow or orange variety. The wonderful smell of a freshly baked sweet potato pie is so fulfilling. The dish needed a bit longer than 1 hour to bake. How to Make Sweet Potato Fluff (My grandmother’s recipe!) 4 cups sweet potatoes ; 1/2 stick butter ; 1 cup sugar ; 1/2 tsp.