One of my go-to summer desserts! You get a fresh, juicy strawberry and tart rhubarb filling topped with a crisp buttery oat crumble. Finish it with a scoop of sweet vanilla ice cream for an indulgent treat no one can resist!
Preheat oven to 400 degrees F. Butter a 3 quart baking dish (I used a 12 by 8 by 2 1/2, a 13 by 9 should work fine too), set aside.
In a mixing bowl, whisk together flour, oats, brown sugar and salt, while breaking up any clumps of brown sugar with finger tips as needed. Add butter and vanilla bean seeds and rub into mixture with finger tips until it comes together in crumbles and no clumps of butter remain. Transfer to refrigerator while preparing filling.
In a mixing bowl toss together strawberries, rhubarb and sugar. Pour into prepared baking dish. In liquid measuring cup whisk together orange juice, orange zest and cornstarch until well blended. Slowly and evenly pour over strawberry rhubarb mixture in pan then lightly toss mixture. Sprinkle crumble evenly over top. Bake in preheated oven 40 - 45 minutes until juices are bubbling and crisp is golden brown. Serve warm with vanilla ice cream.
Don't slice the fruit too small, otherwise it'll turn to mush in the oven.
In a pinch, all-purpose flour can be substituted for cornstarch in the fruit filling (the filling might not thicken as much, but it'll still taste good).