Step 3: Add Butter and Vanilla
Remove from Heat:
Take the saucepan off the heat and stir in the unsalted butter and vanilla extract. Mix until the butter is fully melted and the filling is smooth and glossy.

Step 4: Fill the Pie Crust
Pour Filling into Crust:
Pour the butterscotch filling into the pre-baked pie crust, spreading it evenly.

Cool and Set:
Allow the pie to cool to room temperature, then refrigerate it for at least 4 hours or until fully set.

Step 5: Add Topping
Whipped Cream or Meringue:
Before serving, top the pie with freshly whipped cream or a layer of meringue, depending on your preference. For meringue, make sure to bake it until the peaks are golden.

Step 6: Serve and Enjoy