Make the Pie Crust:

1. In a mixing bowl, combine the flour and salt. Cut in the butter until the mixture resembles coarse crumbs.

2. Add ice water, one tablespoon at a time, mixing until the dough comes together.

3. Form into a disk, wrap in plastic, and refrigerate for 30 minutes.

4. Roll out the dough on a floured surface and fit it into a 9-inch pie pan. Trim and crimp the edges.

5. Preheat the oven to 375°F (190°C). Line the crust with parchment paper and fill with pie weights.

6. Bake for 15 minutes, then remove the weights and bake for another 10 minutes, until golden brown. Let cool.

Make the Butterscotch Filling:

7. In a saucepan, whisk together brown sugar, cornstarch, and salt. Gradually add milk and heavy cream, whisking until smooth.

8. Heat over medium heat, stirring constantly, until the mixture thickens (about 5–7 minutes).

9. In a small bowl, whisk egg yolks. Slowly add a spoonful of the hot mixture to the yolks, whisking constantly to temper them.

10. Pour the tempered yolks back into the saucepan and cook for 2 more minutes, stirring frequently.

11. Remove from heat and stir in butter and vanilla extract until smooth.

12. Pour the filling into the baked pie crust and smooth the top.

13. Let cool to room temperature, then refrigerate for at least 4 hours or until fully set.

Serve:

14. Top with whipped cream and garnish with butterscotch chips or grated chocolate if desired. Slice and enjoy!