Grease 2 muffin tins. Preheat oven to 350 degrees.

To make the topping, combine 1/2 cup of the brown sugar, 1/3 cp of the flour, the butter, and 1 tsp of cinnamon in a small bowl. Toss with spoon until crumbly and set aside.

Whisk together the remaining brown sugar, oil, egg, and vanilla until smooth.

In a large bowl, combine the rest of the flour, baking soda, salt, and cinnamon. Add the oil/brown sugar mixture to the flour mix. Add the buttermilk. Fold in the apples, mixing until just combined. Don't overmix!

Spoon mixture into prepared muffin tins, filling each 3/4 full. Sprinkle each one with topping. Bake for 25-30 minutes, or until golder-brown and a toothpick comes out clean. Enjoy!