Preheat oven to 425ºF.
For the pie crust, using a pastry cutter, combine the flour salt, and butter until it looks like a coarse meal. Add the ice water a tablespoon at a time, just enough until the dough comes together. Form into a disk, wrap tightly in plastic wrap and refrigerate for 30 minutes.
Roll disk out into a 1/4-inch-thick circle, transfer to a pie plate and crimp the edges of the crust.
For the filling, in a mixing bowl, thoroughly combine the Karo syrup, eggs, butter, flour, salt, brown sugar and vanilla.
Fill the crust with pecans to the top and pour the filling over the top of the pecans. Drizzle with molasses.
Bake for 15 minutes then lower the oven temperature to 350ºF and continue to bake for 40 minutes.