2 pounds rhubarb – trimmed and cut into 1-inch pieces
0.75 cups granulated sugar
2 tbsp cornstarch
1.75 cups all-purpose flour
0.5 cups granulated sugar
8 tbsp unsalted butter – cold, cut into small cubes
custard – for serving
Instructions
Heat the oven to 375°F (190°C). Set a 2-quart baking dish on a rimmed baking sheet.
In a large bowl, combine the rhubarb, 0.75 cups granulated sugar, and cornstarch. Toss until the rhubarb is evenly coated, then spread the mixture in the baking dish.
In another bowl, add the all-purpose flour. Add the cold, cubed unsalted butter and rub it into the flour with your fingertips until the mixture resembles coarse breadcrumbs with some pea-sized clumps.
Stir the remaining 0.5 cups granulated sugar into the crumb mixture until evenly distributed.
Scatter the crumble evenly over the rhubarb without packing it down.
Bake until the topping is deep golden and the fruit is bubbling at the edges, 40–45 minutes. If the top browns too quickly, tent loosely with foil.
Let the crumble rest for 10 minutes to set the juices. Serve warm with custard (for serving).