Rhubarb-Peach Crisp

5 cups chopped rhubarb

1 cup chopped peach

1 ½ cups white sugar, or to taste

¼ cup all-purpose flour

1 cup brown sugar

1 cup quick oats

1 ½ cups all-purpose flour

¾ cup butter

Preheat an oven to 375 degrees F (190 degrees C). Lightly grease a 9x13-inch baking dish.

Mix the rhubarb, peach, white sugar, and 1/4 cup flour together in a large bowl until evenly combined; pour into the prepared baking dish and spread into an even layer.

Stir the brown sugar, quick oats, and 1 1/2 cups flour together in a separate bowl. Cut the butter into the flour mixture with a knife or pastry blender until the mixture resembles coarse crumbs; sprinkle evenly over the rhubarb and peach mixture.

Bake in the preheated oven until golden brown on top, about 45 minutes.