You need to make the preferment at least a month before you need to make the hearts.
In a bowl, combine honey and all-purpose flour until homogenous.
Put it in a sealable container and put it somewhere dark and cool for at least a month, and up to three.
Make the dough
Heat the oven to 180°C/350°F/Gas mark 4. If your oven has convection, you should turn it off. If you cannot turn set the heat to 160°C/320°F/Gas mark 3.
Put the egg yolks in a small bowl and mix in the ammonium carbonate.
Mix the potassium bicarbonate into 2 tablespoons of water.
Add the egg mixture, the mixed water, cinnamon, cloves, ginger and extra all-purpose flour to the preferment.
Knead the dough well. You can do it by hand or maschine. It takes from 5-7 minutes.
Bake the hearts
Flour your kitchen counter liberally and roll out the dough to a thickness of about 4 mm. About 1/8th of an inch.
Cut the hearts and put them on a cookie sheet covered in parchment paper. Re-roll the dough and cut our more hearts. Continue until you have no dough left. This dough will make about 20 hearts with the cookie cutter that I am linking. That's about 3 cookie sheets worth.
If there's any left over flour on the hearts, remove it using a pastry brush.
Bake them for 8 to 10 minutes until there is no mark when you press your finger lightly into the heart. Leave them to cool on a wire rack.
They are hard as rocks right after they are baked. Put them in a container and cover it with a wet (but not dripping) dish towel and put them in the fridge for 3 to 4 days.
Cover with chocolate
Temper the chocolate and over the soft gingerbread hearts. Leave the chocolate to set and they are ready to be eaten.