Oregon marionberry pie showcases the state's prized marionberries in a flaky, golden double-crust pie. This beloved Pacific Northwest family dessert bursts with rich, tangy-sweet berry flavor.
Prepare the pie dough by cutting cold unsalted butter into the flour and salt until the mixture resembles coarse crumbs. Drizzle in ice water and gently mix until dough comes together. Divide, shape into two disks, wrap, and chill for at least 60 minutes.
Roll out one disk on a lightly floured surface to fit a 9-inch pie dish. Carefully transfer the dough to the pan, letting the edges overhang slightly.
In a large bowl, gently toss the marionberries with sugar, cornstarch, lemon juice, and a pinch of salt until evenly coated. Let the filling rest for 10 minutes to allow flavors to meld and juice to release.
Pour the berry mixture into the prepared bottom crust. Dot with a few pieces of butter, then roll out the second dough disk and lay over the filling. Trim, fold, and crimp the edges. Cut a few slits in the top crust for steam to vent.
Brush the top crust with beaten egg for shine. Place the pie on a baking sheet and bake in a preheated 400°F (205°C) oven for 20 minutes, then reduce heat to 350°F (175°C) and bake for another 40-45 minutes until the crust is deep golden and the filling bubbles.
Cool the pie on a rack for at least 2 hours to set the filling before slicing and serving.