Preheat oven to 400°F
Grease or line 16 regular sized muffin cups.
For the crumb topping:
Combine all crumb ingredients in a large bowl. Cut with a knife until you get coarse crumbs. Set aside.
For The Muffins:
If you have large blackberries cut them into smaller pieces now.
In a large bowl wisk together all dry ingredients.
In another bowl, wisk together all wet ingredients. Except berries
Pour wet into dry. And stir together until just combined. Do not overmix.
fold in blackberries and their juices carefully.
Pour batter into prepared muffin cups to 3/4 full.
Cover each completely with crumb topping, but not high, just a nice even layer as best you can.
Bake about 15 minutes or until toothpick comes out clean and muffins spring back when lightly touched.
Let stand a few minutes.
Transfer to wire track to cool.
Serve and enjoy. :)
Makes about 16 regular sized muffins.