In a food processor, combine all-purpose flour, sugar, and salt. Cut in cold unsalted butter until the mixture resembles sandy crumbs. Gradually add cold water, pulsing until the dough holds together. Shape the dough into a disc, wrap it in plastic, and chill in the refrigerator for 30 minutes to firm it up.

After chilling, roll the dough into a 12-inch circle on a lightly floured surface. Carefully transfer the rolled-out dough to a tart pan, pressing it into the edges while trimming any excess. Freeze the crust for 10 minutes, then preheat your oven to 375°F (190°C). Blind bake the crust for 15-18 minutes until it's golden brown.

In a saucepan, combine whole milk, heavy cream, and black tea bags over medium heat. Allow the mixture to simmer gently for about 10 minutes, allowing the flavors to infuse. Once fragrant, remove the tea bags and whisk together egg yolks, sugar, cornstarch, vanilla extract, and chai spice in a separate bowl until smooth.

Slowly incorporate the warm milk mixture into the egg mixture, whisking continuously to prevent curdling. Return the combined mixture to the saucepan and cook over medium heat, stirring constantly for about 4 minutes until thickened. Once thick, remove from heat and let it cool for 10 minutes while you prepare the pears.

Thinly slice ripe pears, ensuring they're tender and sweet. Arrange the pear slices decoratively over the cooled custard, encircling the tart. Bake the assembled Chai-Spiced Pear Tart at 350°F (175°C) for 20-25 minutes until the custard jiggles slightly but is set. It should be golden and enticing.

Once baked, allow the tart to cool for at least 1 hour at room temperature. Before serving, dust the top with powdered sugar for a beautiful finish. This Chai-Spiced Pear Tart can be served chilled or at room temperature, perfect paired with honey or whipped cream.