This is the traditional recipe for Greek Easter bread (tsoureki), but shaped in a much easier way, sprinkled with mahleb sugar, and stuffed with some chocolate because why not.
Proof the yeast: Transfer the milk, the yeast, one tablespoon of the white sugar and two tablespoons of the flour to the bowl of your electric mixer and stir to combine. Let it rest until foamy (this is a great way to check if the yeast is active).
Prepare the dough: Add the rest of the flour, the sugar, the butter, the salt, and the spices to the bowl of youe electric mixer. Break the eggs into a small bowl, beat them with a fork, and reserve one tablespoon into a small cup. Add the remaining eggs to the bowl with the rest of the ingredients. Using the dough attachment, knead the dough until very soft and elastic, about 20 minutes (or more!). The dough may be a little sticky, but that’s ok.
First Rise: Let the dough rest in a warm place until tripled in volume (a closed oven with only the oven-light on, should do the trick). It may take 2-3 hours depending on the yeast and the rest of the conditions. When the dough has tripled in volume, knead again for 5 minutes. (At this stage you can store the dough in the fridge for up to 2 days).
Shaping and Second Rise: Line a rectangular cake tin with baking paper. Pinch small pieces of dough, form them into balls between your hands, and transfer them into the cake tin in one layer. Sprinkle with some mahleb-sugar mixture and scatter most of the chocolate eggs among the balls of dough. Continue with the rest of the dough, sprinkling with mahlep sugar from time to time.. You can also place a piece of chocolate in the the center of some of the balls. When all the dough is used, press firmly the surface of the tsoureki with your hands to level it. Transfer to a warm place until almost doubled in volume (about 1-2 hours)
Bake: Beat the reserved egg with 1 tablespoon milk and a pinch of sugar, and gently brush the surface of the bread. Bake for 40 minutes or until a toothpick inserted in the center of the tsoureki comes out clean. If you notice the surface getting brown too quickly, cover it with a piece of foil.
If you use milk chocolate you may want to reduce the white sugar for the dough to 1/3 of a cup (70 grams).