Directions

1. 1

   Pour the instant yeast into a small bowl and set aside. Heat the milk in a small saucepan over low heat until it reaches approximately 160°F, then remove from heat.

2. 2

   Stir the warm milk into the bowl with the yeast.

3. 3

   Let the mixture stand undisturbed for about 5 minutes until it becomes foamy.

4. 4

   In a large mixing bowl, using an electric mixer on medium-high speed, beat together the room-temperature butter and brown sugar until light and fluffy, about 2–3 minutes.

5. 5

   Reduce the mixer speed to medium-low and add the egg, orange juice, and half of the orange zest, mixing until well combined.

6. 6

   With the mixer still running, gradually sprinkle in about half of the all-purpose flour until just incorporated.

7. 7

   Pour in the yeast mixture and continue mixing on low speed. Gradually add the remaining flour, mixing until a soft dough forms and begins to pull away from the sides of the bowl.

8. 8

   Turn the dough out onto a floured work surface and knead it by hand 20–30 times until it forms a smooth ball. If the dough feels excessively sticky, dust with an extra teaspoon or two of flour.

9. 9

   Transfer the dough to a lightly buttered bowl, cover with plastic wrap or a damp towel, and let it rise in a warm place until doubled in size, about 1 to 2 hours.

10. 10

    While the dough is rising, prepare a 9-inch ring mold by buttering the inside. Line a baking sheet with parchment paper and lightly butter the parchment.

11. 11

    Once the dough has doubled, transfer it to the prepared parchment-lined baking sheet and flatten it into a 5-inch disk using your hands.

12. 12

    Using your fingertips, gently press and stretch the dough into an 11-inch circle.

13. 13

    Center the buttered ring mold over the dough circle (you should have roughly a 1-inch border of dough extending beyond the mold). Press the ring mold lightly into the dough to create a crimping guide.

14. 14

    Remove the ring mold and carefully roll the outer edge of the dough inward toward the center, using the crimp line as a guide. You should have a 9-inch round disc with a raised lip around the border.

15. 15

    Press your thumb at regular intervals around the rolled lip to create a decorative crimped seal. Carefully slip the ring mold back over the formed disc (it may require gentle manipulation to fit neatly inside).

16. 16

    Cover loosely with plastic wrap and let the tart rise, uncovered or lightly covered, in a warm place until it has doubled in thickness, about 1 to 2 hours.

17. 17

    While the dough is rising for the second time, combine the fresh blackberries, granulated sugar, corn starch, orange liqueur (if using), and the remaining orange zest in a medium bowl. Gently toss to combine and set aside.

18. 18

    Position the oven rack in the center and preheat the oven to 375°F.

19. 19

    Once the dough has risen fully the second time, use your fingertips to gently poke small wells all over the bottom surface of the dough, being careful to avoid the raised rim.

20. 20

    Spoon the blackberries and all their juices into the center of the dough round in a single layer as much as possible, avoiding the raised rim.

21. 21

    Gently remove the ring mold from around the tart. Brush the exposed dough on the sides and rim with the beaten egg wash.

22. 22

    Sprinkle turbinado sugar evenly over the entire surface of the tart, including the brioche rim.

23. 23

    Bake in the preheated oven for about 25 minutes, until the brioche is puffed and golden brown and the blackberries are bubbling around the edges.

24. 24

    Remove the tart from the oven and allow it to cool on a wire rack while still on the baking sheet for at least 10–15 minutes before slicing.

25. 25

    Slice into 8 wedges and serve warm or at room temperature.