In a small bowl, mix the diced apple and spiced rum.
In a medium bowl, combine the all-purpose and pastry flour, salt, baking soda, baking powder, and apple pie spice.
In the bowl of an electric mixer, cream the butter and sugars until light and fluffy.
Add in the egg and mix until combined.
On low speed add in half the buttermilk and half the dry ingredient mixture and mix until mostly combined.
Add in the remaining buttermilk and dry mixture and mix just until combined.
Fold in the Blue Chair Bay Spiced Rum and apples by hand.
Portion into 12 paper lined muffin tins.
Top with a generous amount of crumb mixture and press the crumbs into the batter a bit.
Bake at 375F for about 25 minutes or until a toothpick inserted comes out clean.
Allow to cool while you make the Blue Chair Bay Spiced Rum Glaze.