Prepare the leaven: Combine the milk, flour, yeast, and sugar in a metal mixing bowl. Stir to dissolve the yeast, and set aside for 20 to 30 minutes until it blooms (puffs up into a sponge).

Prepare the brioche dough: Add 165 grams of flour to the leaven mixture, along with the remaining sugar, salt, egg, zests, orange blossom water, and vanilla bean seeds. Using the dough hook attachment, mix until it forms a rough dough, 3 to 5 minutes. Increase the speed to medium-high, and mix for 2 minutes more.

Add the butter, one piece at a time, while the mixer is on medium-high, making sure each piece is fully blended into the dough before adding the next piece. The dough will start to break down after a few pieces, sprinkle some of the remaining flour (10 grams) into the bowl to help form a more solid dough again. Repeat as needed until all the butter has been incorporated. It should take about 10 minutes to add the butter completely, and you might not need all the flour.

Cover the mixer bowl with a piece of plastic film, and let the dough rest at room temperature until doubled in size, 60 to 90 minutes.

Line a sheet pan with parchment paper.

Place the dough on the pan. Lightly dust top with flour, and flatten into an 8-inch (20-cm) circle (it’s okay to use a rolling pin for this so long as you don’t apply too much pressure).

Use your finger to poke a hole in the center of the dough. Pinch the dough in the center, and fold it outward. Proceed gradually, so as to widen the central hole very gradually until you have a wreath-like circle. Make sure the folded sides are tucked underneath. If you want to include a fevé (bean or trinket) in the cake, now is the time to do so (be sure it’s tuck in tightly so no one sees it).

Cover the cake loosely with plastic film. Let is sit in a warm, but not hot, spot for 45 minutes, to proof until puffed quite a bit.

Preheat your oven to 325ºF (160ºC).

Brush the top with the beaten egg. Sprinkle the pearl sugar on top. Bake for 30 to 35 minutes, until deep golden.

Remove the cake from the oven, and while still hot, decorate the top with the candied fruit. Let cool completely before serving.