Love these berries! Marionberries were first created in Marion County, Oregon-a hybrid of caneberries, similar in its dark color to that of a blackberry, but more the size of a loganberry. I confess to always aspiring to improve my pie-making skills, but when it comes to marionberries,every pie is a star. All this needs are some fresh berries, a bit of sugar, a little thickening and your favorite pastry. Marionberries are very juicy, so this filling is not thick and 'stand on its own' but the flavor is so fresh noone seems to mind.
Roll one pastry disk to fit a deep dish pie pan with a bit of overhang. If you don't have a deep dish, a regular size is fine, you can cut back on the filling if needed. If your deep dish is large, then add another 2 c of berries and increase your thickening agent by about 1 Tblsp.
Gently fold the sugar and cornstarch into the berries and carefully mound them into your prepared pastry. Top the pie with the second crust. Fold the top crust edges under the bottom crust edges and seal as decoratively as you wish. Brush the top with a simple egg wash made with 1 egg and 1 Tblsp. of water. Sprinkle with sanding or granulated sugar if desired. Cut 4-5 small vents in the top.
Bake at 400 for about 40-45 mins. until filling is bubbling and crust is golden.
Serve warm with a nice spoonful of good vanilla ice cream. This is also great cold - as my father-in-law used to say, "we always had pie for breakfast on the farm." :)