Adjust oven rack to medium position and heat oven to 450°F. Line a baking sheet with parchment paper or a silicone baking mat.
Place sweet potato in a large microwave-safe measuring cup or bowl. Cover with plastic with vents poked in it and microwave on high for 5-7 minutes. Add the cream to the sweet potato and puree using an immersion blender (or regular blender).
In a large bowl, mix all purpose and whole wheat flour, sugar, baking powder, salt, baking soda, cinnamon and nutmeg together. Stir in sweet potato until combined. Dough will be soft.
Drop dough into mounds on the baking sheet, spacing them 1 1/2 inches apart.
Bake until biscuits are lightly browned, 15-17 minutes, rotating pan halfway through baking. Let the biscuits cool for 5 minutes and serve warm.
Notes
Instead of using fresh sweet potato for this recipe, roughly 1 1/2 cups leftover cooked, unseasoned sweet potato can be used.