Strawberry-Rhubarb Buckle

Combine rhubarb, strawberries, 1/2 cup sugar, lemon juice and 1 tablespoon of water in a saucepan. Cook, covered, over medium-low heat, stirring occasionally until mixture begins to boil, about 5 minutes. Reduce heat to low.

In a small bowl, stir together remaining 2 tablespoons of water with cornstarch until cornstarch is dissolved. Add mixture to the saucepan and continue cooking fruit until mixture begins to thicken, about 2 minutes. Remove from stove and set aside to cool.

Preheat the oven to 350 degrees F (175 degrees C). Spray a 9-inch deep dish pie pan with non-stick cooking spray, and place on a baking sheet.

Beat 1/2 cup of butter and 1/2 cup of sugar with an electric mixer in a bowl until light and fluffy. Beat in egg, vanilla extract, and yogurt. Add flour, baking powder, baking soda, and salt; mix until just combined. Spread 2/3 of the batter into the prepared pan. Pour strawberry-rhubarb filling on top of the batter. Spread remaining 1/3 of the batter in small mounds atop the filling. Set aside.

Combine brown sugar, 1/4 cup flour, and 2 tablespoons of butter in a small bowl. Mix using a fork, a pastry blender, or your hands, until the mixture resembles coarse crumbs. Sprinkle on top of the batter and filling.

Bake in the preheated oven until the cake topping is nicely browned, about 35 minutes.