# What You'll Need:
→ Crumble base & topping
01 - 1 1/2 cups all-purpose flour
02 - 1 1/2 cups old-fashioned rolled oats
03 - 3/4 cup granulated sugar
04 - 1/2 cup light brown sugar, packed
05 - 1/2 teaspoon fine sea 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 pure vanilla extract
13 - 2 teaspoons fresh lemon juice
# Directions:
01 - Preheat the oven to 350°F. Line a 9x13-inch baking pan with parchment paper, leaving a 1-2 inch overhang on two sides for easy removal.
02 - In a large mixing bowl, whisk together flour, rolled oats, granulated sugar, brown sugar, salt, and cinnamon until evenly distributed.
03 - Pour the melted butter over the dry mixture and stir with a spatula until a cohesive, crumbly dough forms; the texture should hold together when pressed.
04 - Set aside 1 1/2 cups of the crumb mixture for the topping. Press the remaining mixture evenly and firmly into the prepared pan to form the base.
05 - In a separate bowl, toss strawberries and rhubarb with 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 sprinkle the reserved crumb mixture evenly on top, distributing larger clumps for texture.
07 - Bake for 40 to 45 minutes, until the topping is golden brown and the filling is bubbling. Remove from the oven and cool completely in the pan on a wire rack before lifting out using the parchment overhang and cutting into 12 bars.