Strawberry and Rhubarb Crumble

This is the taste of late spring. My parents had a rhubarb plant at my childhood home, and each year there was a bountiful harvest. Other family members sometimes complained about having rhubarb-everything, but I loved it (even the orange-rhubarb jam that never quite jammed). Serve with a scoop of vanilla ice cream. (From Bon Appetit.)

3/4 cup all purpose flour
2/3 cup plus 1/2 cup sugar
large pinch of salt
6 Tbs. (3/4 of a stick) chilled unsalted butter, cut into small cubes
1/2 cup old-fashioned oats (can be made with quick oats)
1/2 cup husked hazelnuts, toasted and coarsely chopped (can sub walnuts)
1/2 vanilla bean, split lengthwise
1 lb. strawberries, hulled and halved (4 cups)
12 oz. rhubarb (bright red), ends trimmed, stalks cut crosswise into 1/2-inch thick pieces

Combine flour, 2/3 cup sugar, and salt in medium bowl; whisk to blend. Add butter. Rub in with fingertips until mixture sticks together in clumps. Mix in oats and nuts. Cover and chill.

Preheat oven to 375°F. Butter 11x7x2-inch glass baking dish.

Place 1/2 cup sugar in large bowl. Scrape in seeds from vanilla bean; whisk to blend well. Add strawberries and rhubarb to sugar in bowl; toss to coat well. Scrape fruit filling into prepared baking dish. Sprinkle oat topping evenly over filling.

Bake crumble until filling bubbles thickly and topping is crisp, about 45 minutes. Let cool 15 minutes. Spoon warm crumble into bowls. Serve with ice cream.