Final answer:
Bread flour is the best choice for making chewy and thick cookies due to its high protein content, which creates more gluten and gives the cookies more elasticity and chewiness compared to other types of flour such as cake flour, pastry flour, and all-purpose flour.
Step-by-step explanation:
The type of flour that would produce the chewiest and thickest cookies is bread flour. Bread flour has a higher protein content compared to cake flour, pastry flour, and all-purpose flour, usually around 12-14%. This higher protein content helps to create more gluten when mixed with liquids, which provides the dough with more elasticity and the resulting cookies with more chewiness.
When comparing to the other flours mentioned, cake flour has the lowest protein content, typically around 7-9%, which makes it suitable for light, airy baked goods like cakes rather than chewy cookies. Pastry flour has a protein content slightly higher than cake flour but still lower than all-purpose flour, making it ideal for pastries and pie crusts, where a tender crumb is desired. All-purpose flour, with a protein content around 10-12%, is versatile but does not provide as much chewiness as bread flour does for cookie baking.