01 - Preheat oven to 400°F.
02 - Place the unbaked pie crust into a 9-inch pie pan and crimp the edges.
03 - Pour 1 1/2 cups water directly into the prepared pie crust.
04 - Combine 3/4 cup sugar and 3 tablespoons flour in a mixing bowl until evenly blended.
05 - Sprinkle sugar-flour mixture over the water in the crust. Drizzle 1 teaspoon vanilla extract and add a pinch of salt.
06 - Cut 4 tablespoons butter into thin pieces and arrange them evenly on top.
07 - Transfer pie to the lower oven rack. Bake at 400°F for 30 minutes.
08 - Reduce temperature to 375°F and continue baking for 20 minutes, until crust is golden and filling is set with a slight jiggle.
09 - Let pie cool completely to room temperature. Refrigerate for a minimum of 2 hours to achieve optimal texture before slicing.