Preheat oven to 350 degrees.
Using a stand mixer with the whisk attachment, cream together butter, sugars, and vanilla. Add egg and whisk until just combined.
In a separate bowl, mix flour, baking soda, salt, and spices.
In two batches, add the dry mixture to the wet mixture, mixing until just combined. Scrape down the sides of the bowl between batches.
Remove bowl from mixer and stir in apples, pecans, and oats using a rubber spatula.
Grease the mini loaf 8-cavity pan with cooking spray and evenly divide dough until each cavity is a little less than halfway full. Smooth the tops with the rubber spatula.
Bake for 16-18 minutes until the tops are golden brown.
Meanwhile, make the icing by combining powdered sugar, heavy cream, and cinnamon in a small bowl and whisking until smooth.
Let bars cool in the pan for 10 minutes before flipping out onto a wire rack to cool completely. Once cool, generously drizzle icing over the bars.
These bars keep well in an airtight container for up to 3 days and they taste even better the second day!
