In a mixing bowl, combine the milk and bananas. Sift in the flour, salt, and baking powder. Thoroughly mix in the eggs and margarine.
Heat the oil in a large skillet to 365 degrees F (180 degrees C).
Carefully place spoonfuls of the mixture into the hot oil and fry until brown. Flip the fritter and continue to brown. Remove fritters from the oil and drain on paper towels. Dust the fritters with confectioners' sugar and serve while warm.