In a large bowl, combine flour, salt and baking powder. Add the cream cheese and incorporate it into the flour mixture by pressing it with your fingers and smashing with your palms. Work quickly until the mixture resembles coarse meal. Add the cubed cold butter and incorporate it into the flour by pressing with your fingers but leaving the butter pieces just flattened and still visible. The mixture should look crumbly with big pieces of crumbs from the addition of butter.
Add the cream and apple cider vinegar and combine until dough is almost coming together. Gather it into a ball, flatten into a disc and wrap with plastic. Refrigerate dough for about 6 hours or overnight. On a floured surface, roll the dough to about 1/4 to 1/8 inch thick and gently wrap it around the rolling pin. Lift it gently over the pie pan, lower and center it down and tuck the dough into the sides of the pan. Cut excess dough on the edge of pie pan and use your fingers or a fork to create decorative borders. Refrigerate dough for at least two hours.
Pre-bake the crust at 425 F for 15 minutes or until the crust is lightly golden. Set aside.
Make the Cheese Filling
In a double boiler, melt the butter and cream cheese together with the milk, cream and sugar. Once the mixture is smooth and the texture is slightly thicker than that of a whipping cream, turn off heat. Stir in the egg, cornstarch, lemon juice and salt. Whisk the mixture until the cornstarch is dissolved and all the ingredients are incorporated. Remove mixture from the double boiler set up and allow to cool slightly. You can cover it with plastic and refrigerate while you preheat the oven.
Preheat oven to 425 F. Set the pan with the crust on a baking sheet so you can easily put it inside the oven. Pour the filling into the pie shell and bake for 15 minutes or so, or until the center looks almost set.