In a mixing bowl, combine all-purpose flour, granulated sugar, and salt. Cut in very cold butter until the mixture resembles coarse crumbs. Gradually add ice water and mix until just combined. Form the dough into a disc, wrap in plastic wrap, and chill in the refrigerator for 30 minutes.

Preheat your oven to 375°F (190°C). Slice pears and toss them in a large bowl with brown sugar, flour, chai spice, fresh ginger, and cardamom. Ensure the pears are thoroughly coated and set aside.

In another bowl, mix rolled oats, chopped almonds, brown sugar, and melted butter until crumbly. Use your fingers to combine, creating a delightful texture.

Roll out the chilled pastry dough on a floured surface to form a 12-inch circle. Transfer the dough into a tart pan, pour the pear filling evenly, and sprinkle the crumble topping over the pears.

Bake the assembled tart for 40-50 minutes, keeping an eye on the crust until golden-brown and the filling bubbles.

Remove the tart from the oven and let it cool for 15-20 minutes before slicing.