→ Fruit Filling
01 - 3 cups fresh rhubarb, sliced 1/2-inch thick
02 - 3 cups fresh strawberries, hulled and halved
03 - 2/3 cup granulated sugar
04 - 2 tablespoons cornstarch
05 - 1 teaspoon vanilla extract
06 - 1 tablespoon lemon juice
07 - Pinch of salt
→ Oat Crumble Topping
08 - 3/4 cup old-fashioned rolled oats
09 - 3/4 cup all-purpose flour
10 - 1/2 cup packed light brown sugar
11 - 1/4 cup granulated sugar
12 - 1/2 teaspoon ground cinnamon
13 - 1/4 teaspoon salt
14 - 1/2 cup cold unsalted butter, diced