Put the ingredients in a plastic bag and mix with a spoon.
Knead the dough from the outside of the bag, until it sticks together.
Roll out the dough as thinly as possible, with a rolling pin on top of the bag (I recommend using a plastic bag a little smaller than the oven pan.)
From the outside of the bag, cut the dough to the cookie size you like, using a knife (The knife won't get dirty.) Open up the bag and line up the cookies on the parchment paper. (See the trick in the next step.)
Put a piece of parchment paper on top of the dough in Step 4. Cover with a baking pan upside down.
Holding the cutting board, flip it over onto the pan, without breaking it up. Peel off the plastic bag, and it's done.
Bake in the oven, preheated to 355F/180C for 15~20 minutes. Leave the cookies to cool in the oven. If they stick together, you can break them apart easily with your hands.
The baking time varies, depending on the dryness of the okara and the thickness of the dough. They're crunchier if you turn them over halfway through baking.
They tend to get soggy, so store leftovers in a plastic container and keep in the fridge! That way, you can enjoy crisp, cold cookies anytime.
Please take a look at the reports of the great arrangements of this recipe from people who've tried adding their own twists.
A related recipe that doesn't require an oven is "Microwaved Okara Cookies" Recipe ID: 1343291
I'm the type that finds washing dishes a pain, so I got the idea of making the cookies this lazy way from another user friend, and changed my method.
For crisp and crunchy cookies, roll out the dough as thinly as possible. They burn easily, so adjust the baking time to your oven. If the cookies aren't crisp enough, turn them over and bake a bit longer. Or, to crisp up, put as many as you plan to eat on a plate and microwave. They burn easily, so warm them up in 30 second increments.