Lightly grease a 9”x9” cake pan. Mix the flour, baking soda and salt together. Stir in the raisins and ginger. Set the mixture aside.
Heat the molasses, brown sugar and butter in a small saucepan over moderate heat, stirring occasionally. When the butter has melted and the sugar has dissolved, remove the pan from the heat and let the mixture cool.
Stir the molasses mixture into the flour mixture and blend the ingredients thoroughly. Add the eggs, one at a time, beating after each addition. Stir in the milk. Pour the batter into the pan.
Bake 40-45 minutes or until a cake tester inserted into the center comes out clean.