- 3 cups chopped rhubarb, or to taste
- Batter:
- 3/4 cup white sugar
- 3 tablespoons butter
- 1 cup all-purpose flour
- 1/2 cup milk
- 1 teaspoon baking powder
- 1 teaspoon vanilla extract
- 1/2 teaspoon salt
- Topping:
- 1 cup white sugar
- 1 tablespoon cornstarch
- 1/4 teaspoon salt
- 1 cup boiling water
- Preheat oven to 350 degrees F (175 degrees C).
- Spread rhubarb into the bottom of a 9×13-inch baking dish.
- Beat 3/4 cup white sugar and butter together in a bowl using an electric mixer until creamy and smooth; stir in 1 cup flour, milk, baking powder, vanilla extract, and 1/2 teaspoon salt. Pour batter over rhubarb.
- Mix 1 cup sugar, cornstarch, and 1/4 teaspoon salt in a bowl; sprinkle over batter. Pour boiling water over sugar mixture layer.
- Bake in the preheated oven until cobbler is lightly browned, about 1 hour.