For dough: In the bowl of a stand mixer, whisk together 3½ cups (438 grams) flour, sugar, kosher salt, yeast, poultry seasoning, and pepper by hand until combined.
In a medium saucepan, heat milk and butter over medium heat until an instant-read thermometer registers 120°F (49°C) to 130°F (54°C). Add hot milk mixture and 1 egg (50 grams) to flour mixture; using the paddle attachment, beat at low speed until a shaggy dough forms.
Switch to the dough hook attachment. Beat at medium-low speed until a smooth and elastic dough forms, 6 to 8 minutes; add up to remaining ¼ cup (31 grams) flour, 1 tablespoon (8 grams) at a time, if dough is too sticky.
Spray a large bowl with cooking spray. Place dough in bowl, turning to grease top. Cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, 40 minutes to 1 hour.
Line a rimmed baking sheet with parchment paper.
Cut top rind off Brie, and discard; place Brie in center of prepared pan.
Punch down dough. Divide into 24 portions (about 32 grams each), and shape each into a smooth ball. Arrange dough balls, seam side down and just barely touching, around Brie. Cover and let rise in a warm, draft-free place (75°F/24°C) until puffed, 30 minutes to 1 hour.
Preheat oven to 375°F (190°C).
In a small bowl, whisk together 1 tablespoon (15 grams) water and remaining 1 egg (50 grams). Brush egg wash onto dough, and sprinkle with sea salt.
Bake until golden brown and an instant-read thermometer inserted in center registers 190°F (88°C), about 20 minutes. Let cool on pan for 5 minutes. Spoon preserves onto Brie. Garnish with rosemary, if desired. Best served warm.