In a large bowl, combine the dry ingredients. In another bowl, combine the liquid ingredients. Add the liquid ingredients to the dry ingredients and stir well. Fold in the blueberries.
Fill 24 greased or paper filled muffin tins 2/3 full with the batter.
Mix up the streusel topping by cutting the butter into the other ingredients with a pastry blender. Sprinkle the topping over the muffin batter.
Bake at 350 degrees for 28- 30 minutes. Yield: 24 muffins.