# What You'll Need:
→ Crumble base and topping
01 - 1 1/2 cups all-purpose flour
02 - 1 1/2 cups rolled oats
03 - 3/4 cup granulated sugar
04 - 1/2 cup light brown sugar, packed
05 - 1/2 teaspoon fine salt
06 - 1 teaspoon ground cinnamon
07 - 1 cup unsalted butter, melted
→ Strawberry–rhubarb filling
08 - 2 cups fresh strawberries, hulled and diced
09 - 2 cups fresh rhubarb, diced
10 - 2/3 cup granulated sugar
11 - 2 tablespoons cornstarch
12 - 2 teaspoons vanilla extract
13 - 2 teaspoons lemon juice
# How-To Steps:
01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - In a large bowl, whisk together flour, rolled oats, granulated sugar, brown sugar, salt, and cinnamon until evenly distributed.
03 - Pour the melted butter into the dry mixture and stir until a cohesive, crumbly dough forms.
04 - Set aside 1 1/2 cups of the crumb mixture for the topping. Press the remaining crumbs firmly and evenly into the prepared pan to create the base.
05 - In a separate bowl, toss strawberries, rhubarb, 2/3 cup sugar, cornstarch, vanilla, and lemon juice until the fruit is evenly coated and the cornstarch is fully incorporated.
06 - Spread the fruit mixture in an even layer over the pressed base, then evenly sprinkle the reserved crumb mixture over the top.
07 - Bake for 40–45 minutes, or until the topping is golden brown and the filling is bubbling. Cool completely in the pan before using the parchment overhang to lift out and cut into 12 bars.