Make the crust by pulsing gluten free flour, sugar, and salt in a food processor. Add cold butter and pulse until pea-sized crumbles form. Add egg yolk and ice water and pulse until dough comes together. Press into a 9-inch pie dish, building up the edges. Refrigerate for 30 minutes.
Preheat oven to 350F. In a large bowl, whisk together eggs, corn syrup, brown sugar, melted butter, vanilla extract, and salt until smooth.
Arrange pecan halves in the chilled pie crust in an even layer. Slowly pour the filling mixture over the pecans. The pecans will float to the top.
Place pie on a baking sheet and bake for 50 to 55 minutes until the filling is set around the edges but has a slight jiggle in the very center. If the crust edges brown too quickly, cover them with foil.
Remove from oven and let cool completely on a wire rack, at least 3 hours, before slicing. The filling will continue to set as it cools.