Preheat oven to 425 degrees F. In a large bowl, stir together baking mix and the 1/4 cup sugar. Cut butter into baking mix using a pastry blender or two forks until mixture resembles coarse crumbs. Make a well in the center of mixture. Add half-and-half all at once. Stir with a fork just until moistened. Stir in Ghirardelli(R) 60% Cacao Bittersweet Chocolate Baking Chips.
On a lightly floured surface, pat dough into a 9x8-inch rectangle about 1/2 inch thick. Sprinkle with the 1 tablespoon sugar. Cut into 16 squares. Bake on a greased baking sheet for 10 minutes or until golden. Transfer to a wire rack; let cool for 10 minutes.