homemade chocolate wafer cookies

My friend Janet made these chocolate wafer cookies and they're sooo good!  They're very soft which I didn't expect.  They're kind of like brownie cookies.  She suggested putting ice cream between two cookies which would've been fantastic but we didn't have any ice cream.  Next time, because there will be a next time. 

homemade chocolate wafer cookies (seeded at the table)
1/2 cup unsalted butter, room temperature
3/4 cup sugar
1/2 cup packed dark brown sugar
1 teaspoon pure vanilla extract
1 cup all-purpose flour
3/4 cup Dutch processed cocoa powder
1/2 teaspoon baking soda
1/4 teaspoon salt
1/4 cup milk

In a large mixing bowl, cream together the butter, sugars and vanilla until light and fluffy, about 2 minutes.  Meanwhile, in a separate medium bowl, whisk together the flour, cocoa powder, baking soda and salt.
Combine the dry ingredients to the butter mixture and stir until incorporated.  Pour in the milk and mix until just combined.
Transfer the dough to a clean workspace and form into two 1 1/2-inch logs.  Wrap tightly with plastic wrap and refrigerate for at least 1 hour.
When ready to bake, preheat the oven to 350 degrees and line two baking sheets with parchment paper.  Use a serrated knife to slice the dough into 1/8-inch disks, working with one log at a time and keeping the other in the fridge until ready to slice and bake.  Place the discs on the prepared baking sheets.
Bake for 8 minutes, rotating the pans halfway through.  Allow the cookies to cool on the pans for 5 minutes before transferring to a wire rack to cool completely.

What Janet has to say- her logs were 2-3 inches in diameter, not 1 1/2 inches.