Rhubarb Raspberry Crisp

About 4 C rhubarb, cut into 1” pieces
2/3 C Sugar
Zest and juice of 1 orange
1 C flour
½ C dark brown sugar
½ tsp. Cinnamon
1 Stick cold, unsalted butter, cut into small pieces
½ C rolled oats
¼ C hazelnuts, skinned and toasted, and chopped (opt)
½ pint fresh raspberries

1.    Heat oven to 350.  Combine rhubarb, sugar, orange zest, and juice in a large bowl.  Stir to combine.
2.    In another bowl, combine flour, brown sugar, and cinnamon. Rub butter into flour mixture with your fingers until it is well incorporated and large crumbs form.  Add oats and nuts and combine.
3.    Turn rhubarb into a 1 ½ quart baking dish, scatter raspberries evenly over surface, and cover with crumb topping.  Bake until topping is brown and crisp and juices are bubbling, about 45 minutes.  Let cool slightly before serving.