Heat the sugar beet syrup, sugar, butter or margarine, and milk in a small saucepan over medium heat for 3 to 5 minutes, stirring until the sugar is dissolved.
Pour the mixture into a mixing bowl and let cool for 5 minutes.
Mix the rock candy, flour, baking powder, and gingerbread spice together.
Knead the dry ingredients into the cooled syrup mixture using the dough hook of a hand mixer.
Cover the dough and let it rest at room temperature for 30 minutes.
Roll out the dough into a rectangle approximately 20 x 30 cm (8 x 12 inches). Cut out about 15 pieces, each approximately 4 x 10 cm (1.5 x 4 inches). Place them on a baking sheet lined with baking paper.
Bake in a preheated oven at 200 °C (392 °F) for 12 to 14 minutes.
Let the Printen cool on a wire rack.
Brush them evenly with the 2 tablespoons of sugar beet syrup and sprinkle with the granulated sugar.
Store the Printen in an airtight container for at least 1 week to allow the flavors to develop. To keep them soft, add a piece of apple, a cotton ball soaked in rum, or a slice of bread to the container.