Okay first of all I have never heard of cooking with potash! Where do you buy it? I know when I worked for CP Rail, we used to ship it as fertilizer all over the globe. Is it possible that they mean salt?
Also what is rock candy? Is that the sugar that comes in all sizes that you put in tea? What does Aachener Printen mean?
Aachener Printen
For best results, use a kitchen scale to make these delicate, but delicious cookies from Germany.
500 grams dark corn syrup
3 tablespoons water
10 grams potash
1 tablespoon rum
150 grams rock candy
100 grams sugar
60 grams candied orange peel, finely chopped
2 teaspoons cinnamon
2 teaspoons aniseed, ground
2 teaspoons coriander, ground
1 pinch cloves, ground
600 grams flour
Some dark syrup and water
In a saucepan over medium heat, stir together syrup and water until hot. Remove from heat and cool slightly. Dissolve the potash in the rum. Break the rock candy into very small pieces. Add all of the ingredients to a large mixing bowl and knead until dough forms. Wrap in plastic wrap and let dough rest for 5 days in a cool place. Preheat oven to 350 F. Grease baking sheets. On a lightly floured board, roll dough out to 1/4 inch thick and cut out 1-inch by 2-inch rectangles. Place cookies on prepared baking sheets, about 2 inches apart. Bake 15 minutes. Allow to cool for one minute on baking sheet and then remove to wire racks to cool completely. Glaze the cookies with a mixture of one part syrup to one part water. When dry, store in tins at room temperature.