Southern-Style Sweet Potato Pie

Ingredients

• 1/2 teaspoon ground cinnamon
• 1 large egg
• 3/4 cup granulated sugar
• 1 teaspoon vanilla extract
• 1/2 teaspoon kosher salt
• 1/4 teaspoon ground nutmeg
• 3 medium to large sweet potatoes (1 1/2 pounds)
• 1 stick unsalted butter, at room temperature
• One 9-inch frozen pie shell or homemade pie crust