Cake: Preheat oven to 350F with shelf in middle of oven.
Butter and flour 3-quart bundt cake pan.
In large bowl of electric mixer, cream butter; add sugar, a little at a time, until light and fluffy; add eggs, one at a time, beating well after each.
Sift flour, baking powder, baking soda, ginger and salt; add to creamed mixture alternately with buttermilk (begin and end with flour); fold in cranberries; spoon batter into prepared cake pan; smooth the top.
Bake 1-1/4 hours or until tester comes out clean; cool on rack 10 minutes; turn out; allow to cool completely.
Glaze: In heavy saucepan, over moderate heat, cook sugar and water; stir and wash down crystals on side of pan with brush dipped in water; add cranberries; bring to a boil; boil, undisturbed, until mixture reaches 250F;.
strain through fine sieve, pressing hard on solids;.