Step 1

Add the butter to the bowl of a stand mixer and beat on medium speed for one minute. Add the powdered sugar. Cream together the butter and sugar on medium-high speed until the mixture turns pale and looks almost fluffy, about 7 minutes, occasionally stopping the mixer to scrape down the sides of the bowl. Add the egg yolk, vanilla extract, and salt and mix until incorporated, about 1 minute. Add the flour and mix on low speed until no dry flour remains, about 1 minute.

Step 2

Turn the dough out onto a large piece of plastic wrap, pat into a disk about 1-inch thick, and wrap well. Chill in the refrigerator for at least 2 hours or overnight.

Step 3

Take your dough out of the refrigerator and let it sit for 5-10 minutes. On a lightly floured surface, roll out the dough into a circle about an 1/8-inch thick and about 11-inches in diameter. Have a 9.5-inch tart pan ready and carefully press the dough into the pan and trim off the excess. Freeze for 30 minutes.

Step 4

Preheat oven to 350°F. Place the tart pan on a rimmed baking sheet. Line the tart shell with parchment paper or aluminum foil and fill with pie weights or dried beans. Bake for 30 minutes. Remove from the oven, let cool for 5 minutes, remove the liner, and bake until golden brown, about 15 minutes. (Don't panic if the tart shell shrinks a little in the oven.) Let cool.

Step 5

In a medium, heavy-bottomed saucepan, add the egg yolks, whole egg, sugar, vanilla extra, and passion fruit puree and whisk together. Gently heat over medium-low heat, whisking constantly, until the mixture has thickened, about 7-10 minutes. Immediately pass through a fine mesh strainer and stir in the butter.

Step 6

Preheat the oven to 325°F. Place the prepared tart shell on a rimmed baking sheet, pour the passion fruit curd into the tart shell, and bake until the curd sets, about 12-15 minutes. To see if it's set, gently tap the edge of the tart pan to see if the center of the tart jiggles. If it doesn't jiggle, it's set. Let cool to room temperature. Serve with whipped cream, if desired.