Preheat the oven to 350 degrees F. Roll and fit a pie crust into a standard 9 inch pie dish. Crimp the edges and place the pie crust in the refrigerator.
Place the cream cheese and brown sugar in the bowl of an electric mixer. Beat on high until light and fluffy, about 3-5 minutes. Scrape the bowl with a spatula, then beat in the eggs. Scrape the bowl again, then set the mixer on low and mix in cream, flour, cinnamon, vanilla, salt and nutmeg until very smooth.
Pour the cinnamon filling into the prepared pie pan. Bake for 35 minutes, until the center seems set when jiggled, but not totally firm. Bake another 5 minutes if needed. Cool completely. Cover and chill.
Take out of the refrigerator 1 hour before serving. Dust the top of the pie with powdered sugar. Cut and serve with whipped cream if desired.
Cover the pie with plastic wrap or aluminum foils and keep in the refrigerator for up to one week.