Preheat oven 350 F. Butter a 2 Qt Dish (9”x9” square dish works well). Make sure the sides are at least 2” tall as the cake will rise during baking. Place the dried cranberries in a bowl and splash on a tablespoon or two of rum (this is traditional but completely optional).
In a medium bowl, cream the eggs and sugar until light colored.
Sift in flour and salt, followed by the milk and rum (if using). Mix until completely smooth and let it rest anywhere from 30 minutes on the counter to covered overnight in the fridge.
Pour batter into dish. Add cranberries gently, distributing them evenly.
Bake off about 60 minutes, until top is completely brown.
Cool 15 minutes in pan, then serve warm. Or, let cool an hour and serve in squares or in long slices.