Grease as 12-cup muffin pan with cooking spray. Set aside. Roll pie dough out to 1/8-inch thickness and use a 3 3/4-inch round cutter to cut 12 circles from the dough, re-rolling scraps as needed. Place each round inside a muffin cup and press the circle into the cup so it’s evenly smooth with the bottom and sides of the muffin cup. (Note: the circle will not come all the way up the side of each muffin cup.) Once all circles have been pressed into pan, freeze for 2 hours or overnight.

Preheat oven to 350°F. Transfer muffin pan directly from freezer to oven until the pie dough is almost cooked through, about 13 minutes. Remove from oven and use the back of a spoon to press down any areas that have puffed up during baking. Set aside.

In a large bowl, whisk together half-and-half and sugar until dissolved. Add eggs and whisk until mixture is homogenous. Add spices, vanilla, and pumpkin; whisk until well combined.

Fill each crust with 1 1/2 tablespoons of pumpkin filling or until the filling almost comes to the top edge of the crust. Bake until filling is set, about 25 minutes.

Allow pies to cool completely before removing from muffin tin and serving with whipped cream and nutmeg, if desired.