From 6 Bittersweets
Adapted from Allrecipes
XIAOLU'S NOTES: I found the melted butter in the streusel to be too much, so I added almost double the amount of flour but only used half of the streusel since I didn't want overwhelming sweetness. I suspect Greek yogurt might work as a healthier alternative to sour cream and will try that next time.
1 (9 inch) unbaked pie crust
3 cups chopped fresh rhubarb
1 cup raspberries [if using frozen, let thaw and drain]
1 large egg
1 teaspoon pure vanilla extract
1 1/4 cups white sugar
1 cup sour cream
1/3 cup all-purpose flour
1/4 teaspoon dried ginger powder
1/2 cup all-purpose flour
1/2 cup brown sugar
1/4 cup unsalted butter, melted
1/4 teaspoon cinnamon
pinch of salt
Preheat the oven to 450 degrees F.
Press the pie crust into a 9 inch pie pan. Spread rhubarb and raspberries in an even layer in the bottom of the crust. In a medium bowl, whisk together the egg, vanilla, white sugar, sour cream, 1/3 cup of flour, and ginger powder until smooth. Pour evenly over the rhubarb.
In a small bowl, mix together 1/2 cup of flour, salt, brown sugar, and cinnamon. [If the pie crust starts warming up, put the filled pie in the refrigerator while you prepare the streusel.] Stir in melted butter until the mixture is crumbly. Sprinkle evenly over the top of the pie.
Bake for 15 minutes in the preheated oven, then reduce the heat to 350 degrees F. Continue to bake for 40 minutes, or until the edges have puffed, and the topping is golden. The center may still be slightly jiggly. Cool completely before slicing and serving.