Start by adding all dry ingredients into a mixing bowl. Whisk together until fully combined.
Next, add all wet ingredients into a large mixing bowl. Whisk together or use a hand mixer.
Pour the dry mixture into the wet mixture. Fold together with a spatula until flour has been absorbed. Pour in apple chunks
Next, add muffin batter into each muffin tin. Use muffin liners or grease with non-stick spray.
Crumble Topping
Add all crumble ingredients into a small bowl. Use a fork or your hands to create the crumble consistency. Using your hands works best! Add to the top of each muffin.
Baking and Cooling
Bake the apple crumble muffins at 350 degrees for 30 minutes.
Remove from the oven when they're done. Carefully remove each muffin if you used muffin liners and place them on a metal cooling rack. If you greased the pan, wait until they're room temperature to remove.