Heat oven to 350°F, grease and flour bottom only of 8 x 4-inch loaf pan.
In large bowl or the bowl of a stand mixer, combine flour, granulated sugar, baking powder and salt. Beat in oil, orange juice and zest, eggs and Greek yogurt until smooth. Stir in cranberries and white chocolate chips.
Scoop the mixture into the prepared loaf pan and spread evenly.
Bake 50 to 60 minutes or until toothpick inserted in center comes out clean. Cool in pan 10 minutes. Remove from pan to a cooling rack. Cool completely, about 1 hour 30 minutes.
In a large bowl, mix powdered sugar, orange extract (or juice and zest, if using instead) and enough milk for the desired consistency. I like mine a little thicker, but add more milk (or orange juice) a tablespoon at a time, if you'd like it thinner. Spoon over the top of the cooled bread, and top with additional dried cranberries and white chocolate chips. Let set to firm up a bit before slicing and serving.