Celebrate spring with these sweet, but tangy crumble bars. They are nice and light, with a perfect balance of sweet and sour.
Preheat oven to 350 degrees. Line an 8x8 baking dish with parchment paper.
In a mixing bowl, add all of the ingredients, and combine until they stick together. Press the mixture into the baking dish, and bake in the oven for 25 minutes. The crust will be a light, golden brown. Let it cool.
Place a small saucepan on medium heat, and add all of the ingredients for the filling. Once it starts to bubble, stir frequently and turn the heat down to medium-low. Cook for 7-8 minutes. Remove from the stove and set aside.
Place all ingredients in a small mixing bowl, and stir until everything is well combined and there are no lumps from the brown sugar.
When you're ready to bake the crumble bars, pour the strawberry rhubarb filling over the crust, and spread it evenly. Sprinkle the topping evenly over the top of the strawberry mixture.
Bake for 20 minutes until the top is slightly browned. Remove from the oven and let it cool on the counter for 30 minutes. Place in the fridge for 1-2 hours to fully finish cooling.
Cut into 12 bars and serve.