For the muffins:
2 cups of all-purpose flour
3/4 cup of sugar
2 teaspoons of baking powder
1/4 teaspoon of ground nutmeg
1/4 teaspoon of salt
1/2 cup of milk
1/2 cup of canola oil
2 eggs lightly beaten
1 teaspoon of vanilla extract
1 cup of fresh blueberries
For the topping:
3/4 cup of all-purpose flour
1/2 cup of packed light brown sugar
2/3 cup of walnut halves coarsely chopped
1/4 teaspoon of ground cinnamon
4 tablespoons of butter cut into small pieces