Toasted Nut Tart

Ingredients

• 0.3 teaspoon double-acting baking powder 
• 1 cup plus light
• 2 tablespoons cornstarch 
• 1 cup t brown sugar dark packed ()
• 1 large eggs 
• 3 large eggs 
• 1 cup flour all-purpose plus more for surface
• 0.5 cup hazelnuts toasted coarsely chopped
• 1 teaspoon kosher salt 
• 0.3 cup pinenuts 
• 0.5 cup pistachios unsalted coarsely chopped
• 2 tablespoons powdered sugar 
• 0.3 cup sugar 
• 0.3 cup butter unsalted ()
• 1 teaspoon vanilla extract 

Equipment

• bowl
• frying pan
• baking sheet
• sauce pan
• oven
• whisk
• wire rack
• hand mixer
• aluminum foil

Directions

1. Whisk 1 cup flour, cornstarch, salt,and baking powder in a medium bowl. Usingan electric mixer, beat butter, sugar, andpowdered sugar in another medium bowluntil pale yellow and well blended, about3 minutes.
2. Add egg; beat to blend, occasionallyscraping bowl.
3. Add dry ingredientsin 3 batches, beating just to blend betweenadditions. Gather dough into a ball; flatteninto a disk. Wrap in plastic and chill for atleast 1 hour. DO AHEAD: Can be made 2 daysahead. Keep chilled.
4. Preheat oven to 375°F.
5. Roll out dough ona lightly floured surface to a 12" round.
6. Transfer to pan. Press onto bottom and upsides of pan. Trim dough flush with top ofpan (reserve any scraps in case needed forpatching crust after baking). Prick doughall over with a fork and freeze for 10 minutes.
7. Line chilled tart shell with foil or parchmentpaper, leaving a 1" overhang. Fill withpie weights or dried beans.
8. Bake until edgesof crust are just beginning to turn goldenbrown, 35-40 minutes.
9. Remove foil and pieweights. Patch any cracks in crust withreserved dough. Return to oven; continuebaking until golden all over, 15-20 minutes.
10. Transfer to a wire rack; let cool completely.DO AHEAD: Can be made 1 day ahead. Storeairtight in pan at room temperature.
11. Preheat oven to 350°F.
12. Place tartpan on a rimmed baking sheet; set aside.
13. Spread out pistachios, hazelnuts, and pinenuts on 3 separate small rimmed bakingsheets. Toast nuts until fragrant and lightbrown, about 5 minutes for pistachios,10 minutes for pine nuts, and 20 minutesfor hazelnuts.
14. Let nuts cool completely.
15. Melt butter in a small saucepan overmedium-high heat. Cook, stirring occasionally,until golden-brown bits form onbottom of pan, about 5 minutes.
16. Removefrom heat and set aside.
17. Stir brown sugar, corn syrup, salt, andvanilla in a medium bowl. Stir in eggs, thenwhisk in browned butter. Fold in nuts.
18. Pourfilling into tart shell.
19. Bake tart, rotating pan halfway through,until filling is set around edges and jigglesslightly in center when nudged, about 1 hour.Loosely tent foil over tart if crust gets toodark.
20. Transfer to a wire rack to cool.DO AHEAD: Can be made 1 day ahead.
21. Letstand at room temperature. Dust withpowdered sugar just before serving.
22. Servewith pistachio or hazelnut gelato, if desired.