4 cups All Purpose Flour
3 teaspoons Baking Powder
3/4 cup Sugar
2 sticks Unsalted Butter, cold
For the chocolate dough
1/4 cup Cocoa Powder
1/4 cup Sugar
2 teaspoons Milk
Combine Flour, baking powder, and sugar. Mix in eggs. Knead in cold butter. Knead until the dough forms a ball. Divide the dough in half. Set aside one of the halves. To the remaining half, add cocoa powder, additional sugar, and milk. Knead until a smooth dough forms.
Roll out each of the two dough halves.
To make checkered cookies, cut each dough half into equal-sized strips. Stack the strips by varying the colors ... for example, on the bottom layer, place a chocolate strip + light strip + chocolate strip side-by-side. On top of this layer, place a light strip + chocolate strip + light strip. On top of this layer, place a chocolate strip + light strip + chocolate strip ... and so on until all the dough has been used. This should create a log. Gently press the log together slightly so that the strips stick together.
To make swirled cookies, roll out the two dough halves into equal sized rectangles. Lay the chocolate layer on top of the light layer. Roll up the dough from the short side. This should create a log. Gently press the log together slightly so that the layers stick together.
Cover the log with plastic wrap and refrigerate for 1 hour.
Preheat the oven to 325 F. Grease a cookie sheet or line the sheet with parchment paper.
The dough log should be firm enough to slice. If it is still too soft to slice, refrigerate for another 30-40 minutes.
Slice the log with a knife into 1/8 inch slices. For softer cookies, slice them a little bit thicker. Place slices onto cookie sheet.
Bake cookies for 10-15 minutes, or until the cookies are just starting to brown. For crispy cookies, bake until a rich golden brown. For softer cookies, bake until just before browning begins.