In a stand mixer, combine flour, sugar, salt, and fresh yeast. Add eggs and knead until smooth (about 10 minutes). Gradually incorporate softened butter while kneading for another 15-20 minutes until sticky and elastic.

Cover the dough with plastic wrap and let it rise in a warm spot for about 2 hours or until it has doubled in size.

In a saucepan, heat whole milk and butter with the split vanilla pod until warm.

In a bowl, whisk egg yolks, sugar, cornstarch, and a bit of flour. Gradually mix in the warm milk, then return everything to the saucepan and cook over medium heat until thickened. Chill the custard completely.

Roll the dough out into a large rectangle, spread chilled custard evenly, and sprinkle mini chocolate chips on top.

Fold the dough over, create layers, and cut into 8 equal pieces. Allow to rise for another 2 hours.

Preheat oven to 350°F (180°C). Brush the tops of the risen brioche with an egg wash.

Bake for 10-12 minutes until golden brown.

Mix equal parts boiling water and sugar to create a syrup. Brush warm brioches with syrup and let cool on a wire rack before serving.

Optionally, dust with powdered sugar before serving.