Fresh Orange Tart with Hazelnut Crust

Ingredients

Orange filling:

• 1 1/4 teaspoons unflavored gelatin
• 1 tablespoon water
• 1 cup Sugar
• 2 tablespoons plus 2 teaspoons finely grated orange peel
• 2 teaspoons finely grated lemon peel
• 4 large eggs
• 3/4 cup fresh orange juice
• 3 tablespoons fresh lemon juice
• 1 cup plus 6 tablespoons (2 3/4 sticks) unsalted butter, cut into tablespoon-size pieces, room temperature

Crust:

• 1 1/4 cups all purpose flour
• 1/2 cup powdered sugar
• 1/4 cup hazelnuts
• 1/4 teaspoon salt
• 9 tablespoons chilled unsalted butter, cut into 1/2-inch cubes
• 1 large egg yolk

Directions

For orange filling:

1. Sprinkle gelatin over 1 tablespoon water in small bowl.
2. Let stand 10 minutes to soften. Combine Sugar, 2 tablespoons orange peel, and lemon peel in medium metal bowl.
3. Using fingertips, rub ingredients together until Sugar is moistened.
4. Add eggs; whisk until smooth. Whisk in both juices.
5. Place bowl over saucepan of simmering water (do not allow bottom of bowl to touch water);
6. Whisk constantly until mixture thickens and thermometer inserted into mixture registers 180 °F, about 5 minutes. Remove from heat.
7. Add gelatin mixture and stir until dissolved.
8. Strain orange mixture into blender; let cool until thermometer inserted into mixture registers 140 °F, about 10 minutes.
9. With blender running, add room-temperature butter 2 pieces at a time and process until blended.
10. Continue blending 3 minutes longer.
11. Transfer filling to bowl; mix in remaining 2 teaspoons orange peel.
12. Cover and chill overnight.
13. For crust:
14. Butter 9-inch square tart pan with removable bottom.
15. Finely grind flour, Sugar, nuts, and salt in processor.
16. Add butter and cut in using on/off turns until mixture resembles coarse meal.
17. Add egg yolk and blend in using on/off turns just until moist clumps form (do not allow dough to form ball). Press dough onto bottom and up sides of prepared pan (crust will be about 1/4 inch thick).
18. Using thumb, press around sides to extend crust 1/4 inch above edge of pan. Chill 1 hour.
19. Preheat oven to 375 °F. Bake crust until golden brown, about 20 minutes.
20. Cool crust completely on rack. (Crust can be made 1 day ahead.
21. Store airtight at room temperature.)
22. Stir orange filling to loosen.
23. Spoon enough chilled orange filling into crust to fill completely.
24. Chill tart at least 1 hour and up to 4 hours.
25. Garnish with candied blood orange slices.
26. Drizzle oranges with some of syrup. Serve cold.