Mix the dry ingredients together and set aside. Combine the eggs, vanilla, pumpkin, vegetable oil and chopped apple until well mixed. Gradually add the dry ingredients until well combined but don't overmix.
Divide batter between 18 muffin tins lined with muffin papers or VERY well greased.
For the topping, work all ingredients together until it forms a coarse meal texture. Sprinkle a teaspoon or two over each muffin until it is all used up.