Step 1

Preheat the oven to 350 degrees. Have two heavy baking sheets at hand (or stack four rimmed baking sheets).

Step 2

Combine the butter, salt, blue cheese, cayenne pepper and flour in a food processor; pulse until a ball of dough forms. Add the optional egg yolk if the dough does not come together, processing until incorporated.

Step 3

Lightly dust a work surface and a rolling pin with flour.

Step 4

Divide the dough in half. Working with one portion at a time, roll out in a rectangle to a thickness of 1/4 inch. Re-dust the rolling pin and/or work surface as needed. Fold and roll as many times (at least six) as needed to form a tidy 6-by-9-inch rectangle.

Step 5

Use a long, sharp knife to slice the rectangle of dough, creating 18 pieces (each 1/2 inch wide, about 6 inches long). Use a thin spatula to transfer them to the baking sheets, arranging them close together but not touching. Repeat with the remaining dough.

Step 6

Sprinkle lightly with salt. Bake one sheet at a time for 20 to 25 minutes or until the straws just begin to brown. Transfer to wire racks to cool.

Step 7

Store in an airtight container.