4 1/4 ounces bread flour, 1 1/3 cups (I feared this could yield a tough consistency, but it´s called for in the original, and nicely offsets rye´s minimal gluten, though it´d probably be fine without)
4 ounces rye flour, 1 heaping cup
1/2 tsp baking soda
3/4 tsp baking powder
3/4 tsp coarse salt
10 Tbsp unsalted butter, softened to room temperature
5 ounces (2/3 cup) brown sugar, packed
4 ounces (1/2 cup plus 1 Tbsp) granulated sugar
1 large egg
1 tsp vanilla
1 4-ounce bar (or more) chocolate of your choosing, chopped into small cubes and bits
Sift together the bread flour, rye flour, soda, powder and salt. Set aside.
Place the butter in a mixer or large bowl, and beat together with the sugars until very light. Add the egg and vanilla, and stir until well combined. Add the flour mixture, stir until just mixed, and then add the chocolate and stir to distribute evenly. Place in a bag or covered container, and chill 2-3 days.
When you´re ready to bake, preheat your oven to 350 degrees, and line a few baking sheets with parchment (or grease them well and hope for the best). Scoop the dough out into cookies -- Torres favors large cookies for a nice crisp-outside-gooey-inside consistency, but I find you can arrive at something similar if you make small cookies and watch them like a hawk.
Bake until golden brown yet soft, 10-15 minutes depending upon cookie size. Let the cookies cool on the sheet for a couple minutes until they firm up enough for you to move them, then transfer to a rack to cool completely (it´s difficult to end up with soft cookies if you don´t pull them soon enough). Devour when warm, with milk, or let cool fully and pack them in an airtight container for your travels.