Step 1

Mix the ingredients of the coating in a small shallow bowl. Reserve.

Step 2

Preheat the oven to 375ºF (190ºC).

Step 3

Grease cookie sheets or line them with parchment paper.

Step 4

Beat butter with sugar for a few minutes in a large bowl, until creamy.

Step 5

Add eggs, one at a time, and beat well.

Step 6

Add vanilla and mix.

Step 7

Sift dry ingredients: flour, cinnamon, cocoa powder, baking soda, cream of tartar, and salt (I measure them and sift directly over the butter, but you can do it in another bowl if you want).

Step 8

Add to the butter and mix well until no dry spots remain.

Step 9

Scoop pieces of dough and make balls the size of walnuts.

Step 10

Roll them in the sugar and place them on the prepared sheets, spacing them a few inches apart to let them expand during baking.

Step 11

Bake for 10 minutes, until the top is dry and the cookies barely start to crackle. It might take a few minutes longer, depending on your oven. I recommend you do a test run with a couple of cookies and check the baking time before you bake them all.

Step 12

Let them cool for 5 minutes on a cooling rack, and remove them carefully with a spatula.

Step 13

Cool the cookies on a wire rack and keep them in tins or airtight cookie jars.