8:00 AM: In your stand mixer bowl, add the 27g of cold water, 1.5g of dry instant yeast, 60g of sugar, and 150g of eggs. Whisk thoroughly by hand until unified. Dump all 300g of bread flour into the bowl (add the optional orange zest here if using). Mix until no dry flour patches remain, cover, and let it autolyse undisturbed for 1 hour.

9:00 AM: Attach your dough hook. Mix on the low speed of your machine for 2 to 3 minutes (or if using a KitchenAid mixer, run it on speed 3 for 3 to 4 minutes) until well incorporated.

Sprinkle in the 6g of salt and mix for a couple more minutes. The dough will gather into a firm, somewhat stiff ball around the hook.

Increase your mixer speed to high and begin dropping in the 150g of soft butter a tablespoon at a time. Knead intensely for 10 to 15 minutes. The dough will look messy at first but will soon incorporate the fat completely, clearing the bowl and making a distinct snapping or popping sound against the walls as a glossy, smooth sheet forms.

Cover and let the dough bulk proof for 3 to 4 hours at a warm temperature of 76–80°F (24–28°C). Perform 2 separate rounds of structural stretch-and-folds during this window; the mass should look noticeably light, airy, and puffy.

1:00 PM: Transfer the covered dough container directly into the refrigerator for a long cold fermentation rest overnight to firm up the high fat content.

8:00 AM: Remove the chilled, firm brioche dough from the refrigerator. Using a bench scraper and kitchen scale, divide the dough mass cleanly into 8 equal pieces weighing roughly 87g each.

Roll each portion firmly against your counter under a cupped hand into a tight, perfectly round ball. Arrange them neatly onto a baking tray lined with parchment paper. Cover loosely and let them proof for 1 to 2 hours at 78–84°F (24–27°C) until they completely double in volume.

Prepare the Pastry Cream: While the rolls proof, warm your 125g of milk and 125g of heavy cream in a saucepan over low heat. In a separate bowl, whisk together the 50g of egg yolk, 50g of sugar, 5g of plain flour, and 10g of cornstarch until smooth. Temper the yolk mixture by slowly pouring a splash of the warm cream mix into it while whisking constantly, then pour everything back into the saucepan. Cook over low heat, stirring continuously, until it thickens into a rich cream. Stir in your vanilla bean seeds, remove from heat, and let cool completely.

Shaping & Baking: Preheat your oven to 375°F (190°C). Brush a layer of egg wash gently over the surface of each puffed brioche roll.

Use your fingertips to press straight down into the exact center of each roll, creating a deep indentation while leaving a proud outer border rim. Fill the cavity generously with your cooled pastry cream and top with fresh seasonal berries.

Slide the tray into the oven and bake at 375°F (190°C) for exactly 10 minutes to lock in a fast oven spring. Lower the oven temperature to 350°F (175°C) and continue baking for 10 to 12 minutes more until the outer borders turn a uniform, rich golden brown. Let cool slightly on a wire rack before serving.