Sweet Potato Crinkle Cookies

Ingredients:
280g plain flour (sifted)
1 tsp baking powder (sifted)
200g mashed purple sweet potato
113g unsalted butter (room temperature)
125g granulated sugar
125g light brown sugar
3/4 tsp salt
1 large egg
Icing Sugar (for rolling and dusting cookies)

Methods:

1. In a bowl add plain flour and baking powder, and whisk to mix.
2. In a stand mixer, add butter and mashed sweet potato and mix using the paddle attachment, using medium speed until smooth and creamy.  Add in both sugars, salt and mix until combined.  Scrap the side of the mixing bowl halfway to make sure it gets everything.  Add in egg and continue to mix for another 2 minutes on speed.
3. Turn the speed to low, add in flour mixture and let it mix until combined.  The dough is very sticky at this point.  Cover with plastic wrap and refrigerate for at least 2 hours or overnight.  (I leave mine overnight).
4. Line a baking sheet with parchment paper.  Scoop about 1 tablespoon of the cookie dough and roll it into a ball.  Generously roll it in icing sugar, place it on the baking sheet, leaving some space in between, and repeat with the rest, making sure that the size of the dough is consistent so that they bake evenly.
5. Bake in a preheated oven of 160 degree Celsius for about 20 minutes (baking time depends on individual oven).  The cookies appear soft when pull out from the oven, but they will toughen up a bit as they cool down.  The inside is still soft and gooey.
6. When cool store the cookies in an airtight container.  This cookies are best stored for a week.

Recipe adapted from "what to cook today" with slight amendments.