Whisk together the flour, salt, ginger and baking powder. Set aside.
In a large mixing bowl beat the butter until creamy, approximately 1-2 minutes, add the sugar and beat, beat in the egg, add the vanilla, rum and milk and combine. Then add the whisked flour mixture and combine, wrap the dough in plastic and chill until firm, approximately 1 hour.
Roll the dough (half at a time if you prefer) out to ¼ inch thick, cut out with your favourite cookie cutters (I used 2-2½ inch / 5-6 cm size cutters) and place on parchment paper lined cookie sheets, sprinkle with granulated or cane sugar and refrigerate while the oven is pre-heating, 15-20 minutes.
Pre-heat oven to 350F (180C).
Bake approximately 8-10 minutes or until lightly browned around the edges. Cool 5 minutes on the sheets then move to a wire rack to cool completely. Enjoy!
Notes
For room temperature ingredients remove from the fridge about 1 hour before using.Store the cookies in an airtight container, with parchment paper between the layers, so that they don't stick. They will keep for two to three days at room temperature.You can also freeze the cookies for up to one month, in a freezer safe container, again separated with parchment paper.