Preheat the oven to 375 degrees F.
Line muffin cups with paper or foil liners or spray muffin tins with cooking spray.
In a medium bowl, whisk the flour with the baking powder and salt.
In a large bowl, combine the sugar, eggs and canola oil and mix until well blended. Beat in the milk and vanilla.
Add the flour mixture to the egg mixture and stir until batter is smooth. Gently fold in the blueberries.
Spoon the batter into the muffin cups, filling them about three-quarters full. Spoon the crumb topping on top of each one and bake for 30 minutes or until the muffins are golden and a toothpick inserted in the center comes out dry.
Cool on a rack for 10 minutes before serving.
TO MAKE THE CRUMB TOPPING
In a medium bowl, combine the flour with the brown sugar, cinnamon and nutmeg. Stir in the melted butter.