Make the Crust:
Mix flour, chopped walnuts, and sugar in a bowl. Rub in the cold butter with your fingers or a pastry cutter until the mixture looks like coarse crumbs. Add cold water, one tablespoon at a time, until dough forms. Press evenly into a 9x13-inch baking pan.
Pre-Bake the Crust:
Preheat oven to 350°F (175°C). Bake the crust for 10–12 minutes until lightly golden. Let it cool slightly.
Prepare the Filling:
In a bowl, whisk honey, brown sugar, eggs, vanilla, cinnamon, and salt until smooth. Stir in chopped walnuts.
Assemble the Pie:
Pour filling over the crust. Spread evenly. Optionally, sprinkle a few walnut halves on top.
Bake the Pie:
Bake at 350°F (175°C) for 30–35 minutes. The filling should be set and slightly golden. Check doneness with a toothpick—it should come out with a few sticky crumbs, not wet batter.
Cool and Serve:
Let the pie cool completely on a wire rack. Slice into squares or rectangles. Serve plain, or with whipped cream or vanilla ice cream.