In a large mixing bowl, combine flour, sugar, ginger and cinnamon. Beat in the eggs, one at a time, using a sturdy wire whisk. Gradually add the milk, continuing to beat until the batter is smooth and satiny, about 5 minutes. Stir int the bananas and let the mixture sit for 10-15 minutes while oil is heating.
When oil is 350-375 degrees, dip out about a quarter cup of the batter and pour it, all at once, quickly, into the hot oil. Let brown 2-3 minutes, then turn with a slotted spoon. If you are not expert at this process, you oil will fluctuate in temperature, so watch carefully and remove fritters when they are rich, golden brown. Lay on clean, absorbent clothes to drain.
Continue until all batter is used. (As you gain coinfidence, you will be able to fry 2 or 3 fritters at a time.) If you want to save some of the batter for later use, cover bowl tightly and refrigerate. The batter will turn a streaky brown, but will be good for 2 or 3 days.) Keep the first-cooked fritters warm in a low oven while you fy more, but eat them as soon as posible. If you like sprinkle confectioners' sugar just before serving.