In a small mixing bowl, combine ingredients for the streusel topping and set aside.
In a large mixing bowl, cream together sugar and butter. Beat in eggs and vanilla.
In another mixing bowl, sift flour, salt, and baking soda.
Add dry ingredients to the sugar mixture in thirds, alternating with the buttermilk (add 1/2 cup buttermilk in between dry ingredients).
Fold in blueberries (or your choice of seasonal fruit). Pour blueberry/batter mixture into a greased 9 x 13” baking dish.
Sprinkle streusel topping evenly over top.
Bake at 350 for 45-50 minutes or until puffy and very golden brown and a toothpick inserted in the centre comes out clean. Let cool slightly before serving. Enjoy.
Notes
* If you don’t have buttermilk on hand (and who does), you can use sour milk instead. Simply combine 1 cup of milk and 1 tsp of white vinegar. Let sit for 15-20 minutes and voila, it’s ready to use.