1 cup flour
1/2 teaspoon salt
1 cup oatmeal
1 cup sugar
1 stick (1/2 cup) butter, at room temperature
1 tablespoon molasses
4 tablespoons safflower or other neutral oil
2 1/2 cups coarsely chopped rhubarb (from about 10 small stalks)
4 cups halved strawberries (from about 1 1/2 quart containers)
3/4 cup sugar
2 tablespoons cornstarch
2 tablespoons orange juice
To make the topping, combine the flour, salt, oatmeal, and sugar, and mix with a standing or handheld mixer. Cut the butter into slices and add them, the molasses, and the oil to the dry ingredients. Mix until well combined–the topping should form big crumbs. Gather into a bowl, cover, and refrigerate up to 3 days if you’re not using the topping immediately.
Preheat the oven to 350°F. In a 9-inch glass pie pan (or an 8-inch square casserole pan), combine the rhubarb, strawberries, and sugar.
In a small bowl, whisk together the orange juice and cornstarch. Pour this over the fruit and toss to combine.
Spread the crumb topping on top of the fruit. Leave most of it in large chunks rather than crumbling it finer.
Place the pie dish on a baking sheet lined with parchment paper (the crisp will bubble over). Bake for 50-55 minutes, until the fruit, is cooked and the crumble is golden brown.
Remove from the oven and let rest at least half an hour before serving.