Beat the eggs and sugar with a hand mixer over high.
Switch your mixer to low, then add the oil and vanilla extract.
Add a cup of flour and the salt, and keep mixing on low.
Dissolve the ammonium bicarbonate in the yogurt and pour it over the dough. Make sure you wait for the yogurt to foam before adding it to the dough.
Let the dough rest in the fridge for an hour and a half.
Take out the dough and slowly mix in the remaining flour with a wooden spoon or a spatula. The dough should have a sticky and pliable consistency.
Let the dough rest for half an hour in the fridge.
In the meantime, preheat your oven to 300°F (150°C).
Take out the dough and start forming the cookies. Scoop a teaspoon of the batter with a greased cookie scoop and shape it in the form of a ball.
Arrange the cookies on a baking tray and bake on the middle rack of your oven for 12 - 14 minutes. The cookies should be slightly pinkish when they're ready.
Leave the cookies to cool down on a wire rack for five minutes.
Carve out the center of the cookies with a paring knife.
Take out the rest of the dough from the fridge and repeat the same process. You should be able to make 4 batches of roughly 20 peach cookies each.
Fill the carved-out cookies with jam and splice them together.
Dip each peach cookie in the yellow food coloring, then half of it in the red one. Leave the cookies on a piece of kitchen paper for a few seconds after dipping, then roll them in the sugar.
Decorate the cookies by placing a mint leaf in between each cookie.