G's kosher for Passover crinkle cookies

My coworker, we'll call her G, makes crinkle cookies every Passover.  These are the cookies that her family eats, even after Passover.  She raves about them - and understandably so.  They're chocolatey and yummy, and best of all, don't taste like Passover cookies!  They look just like regular crinkle cookies, too!

For the past several years, just before Passover, G tells me about all the fantastic things she's making, but you can tell that by the amount of time she talks about these cookies (over the other foods), that these are her favorites.  So when it came to making my list of Passover desserts this year, I asked her for the recipe.  I ran out of time to make all the things on the list, but this year the crinkle cookies made it into the rotation (sadly, the brownies didn't make it in for the seders this year, but maybe during Passover I'll get around to them).

G's Passover Chocolate Crinkle Cookies (I, of course, made a half batch)

Cookies:
2 cups potato starch
1/4 cup oil
3/4 cup cocoa
2 cups sugar
4 eggs

Powdered Sugar:
1 cup + 1 Tbsp sugar
1 Tbsp potato starch

Directions:

Beat one egg at a time, then add potato starch.
Add the rest of the ingredients and mix until a thick paste forms (mine didn't turn into a paste, so I added a little extra oil, but then it still wasn't a paste, so then I just put it in the fridge as it was)
Put in the fridge.

In the mean time, mix the sugar and potato starch, for 10-15 minutes until powdery.

Preheat the oven.  Except the directions don't say what temperature.  When in doubt, I stick with 350F

Assemble cookies:
Coat hands in oil
Form small balls, and roll into powder, put on cookie sheet and bake 10-15 minutes until they start to crinkle.