Apple Pie Muffins

I made these muffins on a total whim the other week.  They were amazing!!!! The house smelled just like fall and there is nothing better than fall in my book!  This recipe is from My Baking Addiction.

2 1/4 cups all-purpose flour
2 tsp pumpkin pie spice
1 tsp baking soda
1/2 tsp kosher salt
1 egg
1 cup buttermilk
1/2 cup butter (melted)
1 tsp vanilla extract
1 1/2 cups packed brown sugar
2 cups Granny Smith Apples (peeled and chopped)

 For Topping:
1/2 cup packed brown sugar
1/3 cup all-purpose flour
1/4 cup rolled oats
1 tsp ground cinnamon
3 tbsp butter (melted)

Heat oven to 375.  Fill a muffin tin with liners and set to the side.  In a large bowl combine the flour, pumpkin pie spice, baking soda and kosher salt.  In a medium bowl whisk together the egg, buttermilk, butter, vanilla and brown sugar. Stir until the sugar is mostly dissolved.  Pour the buttermilk mixture into the flour mixture and stir until combined.  Stir in the chopped apple pieces.  Fill each muffin liner until 3/4 full.  In a small bowl make the topping by combining the brown sugar, flour, oats and cinnamon.  Pour in the butter and stir until it's mixed well.  Sprinkle over the muffins. Bake for 25 minutes or until muffins are cooked through. Let cool in the muffin tin for 5 minutes then remove.