One and a half cups of all-purpose flour for the pie crust Half a teaspoon of salt Half a cup of cold, cubed unsalted butter and half a cup of ice water
For the filling of butterscotch: One cup of packed brown sugar and one-half cup of unsalted butter Half a cup of cornstarch Two cups of whole milk
To make the dough, combine the flour and salt in a large bowl. Using a pastry cutter or fork, chop in the butter until the mixture looks like coarse crumbs.
Add Ice Water: Stir the dough until it holds together as you gradually add ice water. Form into a disc, cover with plastic wrap, and chill for half an hour.
Preheat the oven to 375°F (190°C) before rolling and baking. Line a 9-inch pie pan with the rolled-out dough. Line with parchment paper, prick the bottom with a fork, and then fill with dry beans or pie weights.
Bake: After 15 minutes of baking, take off the weights and continue baking for 10 more minutes, or until golden brown. Allow to cool fully.
Caramelize the Sugar: Melt the butter and brown sugar in a skillet over medium heat, stirring continuously, until the mixture is bubbling and deeply caramelized.
To thicken the mixture, whisk together the cornstarch, milk, egg yolks, and salt in a another bowl. Stirring, slowly pour into the saucepan. Cook for approximately five minutes over medium heat, or until the mixture thickens.
Finish with Vanilla & Cream: Take off the heat and, for added smoothness, mix in the heavy cream and vanilla essence.
Pour into Pie dough: After allowing the filling to cool a little, pour it into the pie dough that has been baked. Refrigerate until firm, at least 4 hours, after smoothing the top.