Mix flour and honey until fully combined.

Place in a container with a lid. Make sure you will be able to get the dough out again as it can go rock hard while it sits. One way to aid this is by forming smaller balls of dough instead of one big ball.

Hurry up and wait. Let the pre-dough rest for at least 1 month in a cold place before moving on to the next step.

 Combine the egg yolks with the potash, make sure there are no clumps left.

 Add the egg yolks to the pre-dough, as well as the remaining ingredients: cinnamon, cloves and hartshorn salt.

 Knead the dough. This takes time. Count on using about 8 min if you do it by hand or 6 if you are using a kitchen machine (do 3 min on a low setting and then 3 on the highest possible setting).

 Roll out the dough to a thickness of roughly ⅛ inch (4 mm). Cut out heart shapes. Continue until all the dough has been made into shapes.

 Place the shapes on a baking tray and bake them for 8-10 min at 356 F (180 C). Carefully test if the honninghjerter are done by feeling them. If they collapse then they aren’t ready yet.

 Fully cool the shapes on a wire rack.

 Your honninghjerter should now be rock solid. Place the honninghjerter in a container and cover them with a moist kitchen towel. Place them in the fridge for 3-4 days.

 Only take out as many honninghjerter as you plan to eat. Honninghjerter will keep at least for a month in the fridge if you leave them in the container until you want to serve them.

Add a filling if you want to.

Cover with your desired glazing and let dry.

Enjoy the honninghjerter at long last.