Fukuwatashi Senbei knockoff recipe

This weekend, my wife and I decided to replicate Fukuwatashi Senbei cookies, those delightful specialty cookies that you can buy at Minamoto Kitchoan.

Here’s the recipe we used:

Ingredients:
1 1/2 cups butter, softened
1 1/4 cups white sugar
4 eggs
1 teaspoon vanilla extract
5 cups all-purpose flour
2 teaspoons baking powder
1 teaspoon salt
cocoa powder
1 cylinder of store-bought white frosting (or you can make your own)

1. Leave the butter out on the counter to soften (~30 min)
2. Mix butter, sugar, eggs and vanilla in a bowl with an electric mixer.
3. Add flour, salt and baking powder and kneed until smooth
4. Place dough in freezer and preheat oven to 400
5. Roll thin (1/8 inch) on a floured surface and cut into circles (~3in diameter)
6. Set a small portion of dough aside and mix in cocoa powder to taste. Place small balls of this cocoad dough in the middle of each cookie and smoosh in.
7. Bake at 400 for 6 1/2 minutes
8. Place cookies on plate to cool and then double them up with a thin coat of the frosting

The flavor, at least, was close. The only way I can think to get closer would be to replace the butter with Crisco (you can taste the hydrogenated fat in the actual cookies). And, of course, I have no idea where I would get a cooling rack that would impart those characteristic ridges.