Knead all ingredients together with your hands (or possibly with a mixer with dough hooks). Once you can form a ball, the dough is ready.
Wrap the dough in cling film and let rest in the refrigerator for 30 minutes. You can also skip this step, but it will make your gingerbread cookies grittier and less crunchy.
Preheat the oven to 180 °C / 356 °F.
Cover a baking tray with parchment paper and take the dough out of the refrigerator.
Turn the dough into very small marbles (maximum Ø1 cm / 0.4 inch) and place them on the baking tray. You don't have to press them.
The peppernuts will grow much bigger during baking so leave enough space between the spice nuts.
Bake the gingerbread cookies for 15-20 minutes. We bake about 120 gingerbread cookies in the oven in 2 times. Let the gingerbread cookies cool completely before eating or storing them in an airtight cookie jar.
Tip: turn it into chocolate gingerbread cookies by melting chocolate a bain-marie in a pan and putting the cooled gingerbread cookies through the chocolate.