Wash and dry the sweet potatoes and poke all over with a fork, then place the potatoes on a plate and microwave for 8 to 14 minutes until they are fork tender.
While the potatoes cook, prepare the crusts by rolling out the dough on a lightly floured surface and using a 2½- inch round biscuit or cookie cutter to cut out 24 circles from each sheet of crust. You’ll want to roll the dough out quite a bit as you don’t need it to be as thick as it is out of the box because the pies are so small.
Gently press each circle of pie crust into an ungreased mini muffin pan cavity. You can add small strips of parchment under each one to help get it out after baking.
Once cooked, peel the potatoes and add the flesh to a large mixing bowl. Use a hand masher, hand mixer, or stick blender (for smoothest filling) to mash the sweet potatoes.
Once the potatoes are smooth, add the sugar, heavy cream, cinnamon, vanilla, and salt and mix until fully combined.
Preheat the oven to 425 degrees F.
Use a small cookie scoop to add the filling into the prepared pie crusts, about 1 tablespoon of filling each. Use the back of a spoon or rubber spatula to gently smooth the filling into the crusts.
Bake for 15 to 18 minutes.
Remove from the oven and transfer the pies to wire racks to cool before topping with whipped cream and cinnamon and enjoying.