For helpful tips on making the crust, please see my sour cream pie crust recipe.In a small bowl, whisk together the sour cream and egg yolk until combined, set aside. In the work bowl of a food processor, pulse the flour, sugar, and salt a few times to combine.
Add the butter and pulse until butter is in pea size pieces, about 10 pulses, do not over mix. Add half the sour cream and egg mixture and pulse about 5 times, or until well combined. Add the remaining sour cream mixture and pulse/process until it comes together completely. Gather the dough together into a smooth ball, wrap tightly with plastic wrap, and refrigerate for 30 minutes.
Make the Cranberry Filling
Heat a medium sized pot over low/medium heat on the stove. Add all the ingredients except the cornstarch. Stir to combine. Simmer for about 25 minutes or until the cranberries have burst and begun to reduce.
Once cranberries have burst, combine the cornstarch with enough cold water to dissolve it, stir in the cornstarch mixture. If the mixture is very thick, remove from heat and set aside.
If it is still liquidy, simmer an additional 5-10 minutes until thickened, remove from heat and set aside. Once mostly cooled, the filling should be the consistency of a thick jam.
While the cranberry filling cools, combine all streusel topping ingredients in a small bowl and mash with a fork until well mixed.
Roll the Pie Crust
Preheat oven to 350℉. When the pastry dough is cold, use a rolling pin to create a circle about 10 inches around. Carefully transfer the crust into a 9-inch pie pan, and gently press it into place. Trim excess dough from the edge, then flute the edges using your thumb and forefinger.
Fill the crust with the cranberry filling. Grab handfuls of the streusel topping and squeeze tightly to form a large lump. Break it apart over the cranberry filling, creating smaller crumbles of streusel. Cover as much of the pie as you’d like. I recommend leaving a small area around the edge uncovered so you can see the cranberry filling.
Bake in the preheated oven for 35-45 minutes. Check the pie at 35 minutes and make sure the edges aren’t over-browning. If the crust is getting too brown, cover it with a pie crust shield or aluminum foil.
The cranberry pie is finished baking when the filling no longer jiggles. Allow the pie to cool at room temperature for at least 2 hours before slicing.
Notes
Helpful Tips from Liz
To make the pie crust without a food processor, use a pastry cutter for each step in place of the food processor. Switch to using your hands after the second addition of sour cream mixture to bring the dough together.
For the flakiest pie crust, be sure to use cold ingredients.
To prevent the crust from being tough/dry, avoid over mixing the pastry dough.
To create the cleanest slices, cut the cranberry pie when it's cold.