- In a stand mixer fitted with the dough hook, combine the flour, sugar, yeast and salt. Add the eggs and lemon zest. Mix just until the dough starts to form.
- Add the butter and knead the dough for 5 minutes. The dough will be soft and very sticky. Transfer to a clean, lightly oiled bowl. Cover with plastic wrap. Let rise in a warm, humid spot for 2 hours or until doubled in volume.
Orange Blossom Pastry Cream
- Meanwhile, in a pot off the heat, whisk together the sugar, cornstarch and flour. Add the eggs and whisk to combine. Stir in the milk and vanilla. Cook over medium-high heat, stirring constantly and scraping the bottom and sides of the pot, just until the mixture thickens. Remove from the heat. Stir in the butter and orange blossom water. Pass through a sieve set over a bowl to remove any lumps.
- Cover with plastic wrap directly on the surface of the cream. Let cool, then refrigerate for 2 hours or until completely chilled. When ready to use, gently mix with a spatula until creamy and smooth.
- Butter the sides of an 8-inch (20 cm) springform pan. Line the bottom of the pan with parchment paper. Butter the paper.
- On a lightly floured surface, knead the brioche dough for 1 minute, then form it into a ball. With a rolling pin, roll out the dough to form an 8-inch (20 cm) disc. Place in the prepared springform pan. Cover with plastic wrap. Let rise in a warm, humid spot for 1 hour 30 minutes.
- With the rack in the middle position, preheat the oven to 350°F (180°C).
- In a small bowl, combine the egg and cream with a fork. With a pastry brush, brush the dough with the egg wash. Sprinkle the surface of the dough with the pearl sugar.
- Bake for 25 minutes or until the brioche is golden. Let cool completely on a wire rack. Run a thin blade between the brioche and the sides of the pan and unmould.
- Cut the brioche in half horizontally to get two layers. Spread the pastry cream over the bottom layer, leaving a 1/2-inch (1 cm) border all the way around. Cover with the second layer. This dessert is best served the same day.
Pearl sugar can be found in fine grocery stores and specialty shops. If unavailable, use sugar cubes crushed with a mortar and pestle until the size of peppercorns.