Creating Cranberry Custard Pie is simple when following these step-by-step instructions:

1. Preheat the Oven: Preheat your oven to 350°F (175°C).
2. Prepare the Pie Crust: Place the pre-made pie crust in a 9-inch pie plate. Crimp the edges or make decorative patterns if desired.
3. Prepare the Cranberries: Rinse the cranberries under cold water. If using frozen cranberries, do not thaw.
4. Mix the Custard Filling: In a large bowl, whisk together the eggs, granulated sugar, heavy cream, vanilla extract, cornstarch, salt, and optional orange zest until smooth and well combined.
5. Add Cranberries: Fold the cranberries gently into the custard mixture until they are evenly distributed.
6. Pour into Crust: Carefully pour the custard and cranberry mixture into the prepared pie crust.
7. Sprinkle Cinnamon: If desired, sprinkle the ground cinnamon on top for added flavor.
8. Bake: Place the pie in the preheated oven and bake for 40-45 minutes, or until the custard is set and the top is slightly golden.
9. Cool the Pie: Remove the pie from the oven and allow it to cool for 15-20 minutes before slicing.
10. Serve: Enjoy warm, at room temperature, or chilled.

These steps will guide you in creating this amazing Cranberry Custard Pie effortlessly.