Preheat oven to 325.
In large bowl mix together your flour, baking powder and pumpkin pie spice, set aside
In another bowl with hand mixer beat together our brown sugar and butter until light and fluffy, add in your eggs one at a time.
Mix in your vanilla and sweet potatoes and mix well until combined.
Alternation in 3 separate additions add 1/3 of your flour mixture to wet ingredients and mix well. Add in your milk, mix well and repeat until flour and milk are combined then add in your bourbon until incorporated.
Spray a mini bundt cake pan with non-stick cooking spray and fill about 3/4 the way full with batter and bake for about 15 minutes or until tops spring back.
Remove from oven, let cool for a few minutes before turning out onto cooling racks, repeat with remaining batter.
Meanwhile to make buttercream in large bowl beat your butter until light and fluffy, adding 1 cup at a time add in your powdered sugar.
Mix in your maple extract and heavy cream if desired for consistency.
Add your buttercream to piping bag fitted with large open start tip, pipe onto tops of cooled cupcakes, place in freezer while you make your butter pecan glaze.
To make glaze add butter, salt and sugar into medium sauce pan and heat on medium heat until melted and sugar is dissolved, Stir in your heavy cream and continue to heat and stir constantly until thickend slightly, stir in your chopped pecans.
Remove your mini bundt cakes from freezer and drizzle with butter pecan sauce, place back in refrigerator or freezer to quickly cool sauce if desired.