Mix first 3 ingredients in a large bowl.
Stir together mashed blackberries with next 5 ingredients.
Fold wet ingredients and blackberries into dry ingredients. Stir until mixed.
Prepare standard sized muffins tins by spraying with non-stick spray or lining with cupcake wrappers.
Fill tins 2/3 full with batter.
Bake in a 400 degree oven for about 20 minutes or until a toothpick inserted comes out clean.
Cool for 5 minute before removing from pan.