In a medium bowl, blend topping ingredients together with a fork or pastry blender until crumbly, and set aside
Preheat oven to 350º
Combine flour, baking soda, salt, cinnamon, and nutmeg together in a medium bowl, and set aside
In a larger mixing bowl, whisk eggs and brown sugar together for 1-2 minutes, until the mixture becomes lighter
Whisk in milk, vanilla extract, oil
Stir in dry ingredients until just combined, and then fold in apple chunks
Divide batter evenly between 12 greased or paper lined muffin tins
Sprinkle generously with crumble topping
Bake in center of oven for 15 minutes, or until toothpick inserted in the center comes out clean
Remove from oven and let cool before serving