Ingredients
1/4 cup unsalted butter at room temperature
1 cup sugar
1 tsp vanilla extract
1 large egg
2 cups all-purpose flour
1 tsp baking pdr
1/2 tsp baking soda
1/2 tsp salt
1 cup buttermilk
2 1/2 cups rhubarb diced
For the topping:
1/4 cup butter melted
1/2 cup flour
1/2 cup sugar
Preparations
Preheat the oven to 350 degrees F. Grease a 8×8 inch square baking pan.
Cream the butter and sugar in a large mixing bowl. Add the vanilla extract and egg and beat until combined.
In a small bowl, combine the flour with the baking powder, baking soda, and salt.
Using a rubber spatula, fold the flour mixture into the wet mixture, alternating with the buttermilk. Be careful not to over-stir. Some flour lumps will remain and that is okay. Stir in the rhubarb.
Spoon the batter into the greased baking pan.
To make the topping, combine all the ingredients and crumble with your fingers. Evenly sprinkle the topping over the cake batter.
Bake the cake for 35-45 minutes or until a toothpick inserted into the center of the cake comes out clean.
Let the cake cool before cutting into squares. Serve with ice cream, whipped cream, or homemade vanilla sauce.