Preheat oven to 180 degrees C. Spray 23cm ring tin lightly with cooking spray and dust with flour.
In a medium bowl, combine flour, baking soda, salt, cinnamon and allspice.
In a large mixing bowl, cream 125g butter, white sugar and 3/4 cup brown sugar. Mix in eggs, 1/3 cup rum and vanilla. Mix in flour mixture in three additions alternately with apple sauce, ending with flour. Stir in dried cranberries. Spoon batter into prepared pan.
Bake in preheated oven for 45 to 55 minutes, or until a toothpick inserted into the cake comes out clean. Cool cake in pan for 15 minutes, remove from pan and cool completely on a wire rack.
In a small saucepan, melt 3 tablespoons butter. Stir in 1/4 cup brown sugar, icing sugar and 2 tablespoons rum. Heat until smooth; if mixture is too thick, add water and maybe a little more rum. Drip glaze over cooled cake.