Prepare your pie dough if using a homemade pie crust. Roast sweet potatoes. Start by preheating the oven to 400 degrees. Then, clean the sweet potatoes and then prick all over with a fork and place them on a sheet pan lined with foil or parchment paper. Bake the sweet potatoes until they are tender (about 60-70 minutes). Remove them from them oven and allow them to cool.
Make the brown butter. Add the diced butter to a small skillet or pot. Heat the skillet to medium heat. The butter will start to melt as the skillet heats up. Allow the butter to bubble and “cook” until it begins to change from a bright yellow color to a golden brown color. You will know the butter has “browned” when you see brown bits beginning to form in the bottom of the skillet or pot. Remove the butter from the heat and transfer to a heat safe dish.
Pre-bake the pie crust. Pre-bake your pie crust according to the recipe instructions (or package instructions if using store-bought crust). Set aside when done. Make the Filling. Once the sweet potatoes are cool, peel the sweet potatoes. Next, place the sweet potatoes in a blender until they are smooth (we don't want any strings). Once blended, measure 2 cups of pureed sweet potato and set aside.
Next, in a large bowl, add the pureed sweet potatoes, browned butter, sugar, vanilla extract, heavy cream, cornstarch, eggs, spices, and salt. With an electric mixer, mix the ingredients on medium-low until well combined to create the filling.
Next, place the pie crust on a sheet pan. Then, pour the pie filling into the crust. Bake the pie at 350 degrees for 55-60 minutes until set. A slight jiggle is ok.
Remove the pie from the oven and let cool on a wire rack until room temperature.
Serve a slice of pie at room temperature or chilled with a dollop of whipped cream and a little sprinkle of cinnamon on top.