Preheat oven to 200 degrees Celsius (180 degrees Celsius fan-forced). Move the oven rack to the middle of the oven.Line 12 holes of a muffin pan (1/3 cup capacity holes) with patty/muffin cases. We use cases that measure 5cm across the base, 8cm across the top, and 3.5cm from base to top.Place flour and brown sugar in a large bowl and stir together, breaking up any lumps of sugar. Add chocolate chunks to the flour mixture and stir to distribute.