Created by Kittencal on March 9, 2013
Step 1: Preheat oven to 350 degrees F.
Step 2: Grease a 13 x 9-inch baking dish.
Step 3: In a small bowl using fingers mix together the topping ingredients until crumbly; set aside.
Step 4: In a large bowl cream 1/2 cup soft butter with sugar until fluffy (about 2 minutes).
Step 5: Add in egg and vanilla; beat until well combined.
Step 6: In a small bowl mix together 2 cups flour with baking soda, salt and a pinch of nutmeg; add to the creamed mixture alternately with buttermilk.
Step 7: Toss the chopped rhubarb and blueberries with 1 tablespoon flour then stir into the batter along with the walnuts.
Step 8: Sprinkle the prepared topping mixture evenly over the top of the batter.
Step 9: Bake for about 45-50 minutes.
Step 10: Serve cake warm with vanilla ice cream or whipped cream.