In a large mixing bowl, combine the flour, brown sugar, baking soda, salt and pumpkin pie spice.
Once you have the dry ingredients combined well, add the applesauce, egg and shortening.
Once your ingredients are fully combined, pour the cake batter into a greased metal 9 x 13 cake pan. Bake for 15 minutes then insert a toothpick into the center to test to see if it's done. If the toothpick comes out clean, remove from the oven and allow it to cool completely in the pan. If it is not done, bake for 5 minutes more and check again.
While the cake is cooling, melt the butter in a medium saucepan on med/low until it has started to turn a golden brown color.
When it has melted and cooked the way you want, remove it from the heat and add the vanilla extract and milk then use a wire whisk to gently stir it.
Add 1 1/2 cup powdered sugar and mix well by hand.
Pour the frosting base into a medium mixing bowl once you have the initial powdered sugar added. Next, add powdered sugar 1/2 cup at a time until you have a thick and fluffy frosting.
After your applesauce cake has cooled completely, spread the buttercream frosting evenly on top.
Remove the cake from the baking pan and cut into bars. Store your applesauce cake bars in an airtight food storage container in the fridge.
Applesauce Cake Bars with Buttercream Frosting https://sixdollarfamily.com/applesauce-cake-bars-with-buttercream-frosting-recipe January 4, 2019