In a large bowl, I whisk 2 ½ cups flour, 1 tsp salt, and 1 tbsp sugar. I cut in 1 cup cold butter using a pastry cutter until pea-sized crumbs form. I add 6–8 tbsp ice water, 1 tbsp at a time, mixing until the dough just holds together. I divide into two disks, wrap, and chill for 30 minutes.

In a large bowl, I gently toss 5 cups huckleberries with ¾ cup sugar, 2 tbsp lemon juice, 1 tsp vanilla extract, ¼ tsp cinnamon, and 3 tbsp cornstarch. I let it sit for 15 minutes to hydrate the cornstarch, ensuring a set filling for Huckleberry Pie.

On a floured surface, I roll one dough disk into a 12-inch circle and fit it into a 9-inch pie dish, trimming excess. I roll the second disk for a lattice or full top crust.

I pour the huckleberry filling into the crust, spreading evenly. For a lattice, I cut the second dough into 1-inch strips, weave over the filling, and crimp edges. For a full crust, I cover the filling, cut vents, and crimp. I brush with egg wash (1 egg + 1 tbsp milk) and sprinkle with coarse sugar.

I place the pie on a baking sheet and bake at 400°F (200°C) for 20 minutes, then reduce to 350°F (175°C) for 30–35 minutes, until the filling bubbles and the crust is golden. If edges brown too quickly, I cover them with foil.

I cool the pie for 3–4 hours on a wire rack to set the filling. I slice and serve at room temperature, savoring the juicy, tart-sweet flavors.