Preheat oven to 425 F. Move rack to middle third of the oven. Line muffin tin with paper liners.
Thoroughly stir together flour, 1 cup sugar, Clabber Girl Baking Powder, ground ginger, cinnamon, salt, and baking soda in a large bowl. In a small bowl, stir together 3 1/2 tbsp sugar and cranberries; set aside.
In a 2-quart bowl, combine melted butter and milk. Then, using a fork, beat in the eggs, crystallized ginger (if using), and orange zest until well blended. Add milk mixture to flour mixture, stirring gently just until dry ingredients are evenly moistened and incorporated; don't over-mix or the batter may toughen. Gently stir in the cranberry-sugar mixture just until evenly distributed throughout.
Divide batter into muffin tin. Sprinkle muffin tops with reserved 1 1/2 tablespoons sugar, dividing it among them.
Bake for 14 to 18 minutes or until a toothpick inserted into the thickest part comes out clean. Cool on wire rack 3 or 4 minutes, then remove muffins and let cool completely.