Step 1: Prepare the Linzer Pastry Crust: In a large bowl, whisk together the all-purpose flour, almond flour, granulated sugar, cinnamon, and salt.
Step 2: Add the cold, cubed unsalted butter to the dry ingredients. Using a pastry blender or your fingertips, cut the butter into the flour mixture until it resembles coarse crumbs with some pea-sized pieces remaining.
Step 3: In a small bowl, whisk the egg yolk and vanilla extract. Add this mixture to the flour mixture and mix until the dough just comes together. Do not overmix. Form the dough into a disc, wrap tightly in plastic wrap, and refrigerate for at least 30 minutes, or up to 2 hours.
Step 4: Preheat oven to 375°F (190°C). On a lightly floured surface, roll out the chilled dough into a 12-inch circle. Carefully transfer it to a 9-inch tart pan with a removable bottom. Press the dough gently into the bottom and up the sides. Trim any excess dough. Prick the bottom with a fork several times.
Step 5: Line the crust with parchment paper and fill with pie weights or dried beans. Blind bake for 15 minutes. Remove the parchment and weights, then bake for another 5-7 minutes, until lightly golden. Let cool slightly.
Step 6: Prepare the Pistachio Cream: Reduce oven temperature to 350°F (175°C). Spread shelled pistachios on a baking sheet and toast for 5-7 minutes, until fragrant. Let cool completely. In a food processor, pulse the toasted pistachios until finely ground.
Step 7: In a medium bowl, cream together the softened unsalted butter and granulated sugar until light and fluffy. Beat in the egg, almond extract, and vanilla extract until well combined. Gently fold in the ground pistachios and all-purpose flour until just combined.
Step 8: Assemble and Bake: Peel, core, and halve the pears. Slice them thinly crosswise. Pour the pistachio cream into the partially baked Linzer pastry crust, spreading it evenly. Artfully arrange the pear slices over the pistachio cream, fanning them out or creating a circular pattern.
Step 9: Bake the tart at 350°F (175°C) for 40-50 minutes, or until the pistachio cream is set and lightly golden, and the crust is deeply golden brown. If the edges brown too quickly, loosely cover them with aluminum foil.
Step 10: Let the Pear and Pistachio Cream Tart with Linzer Pastry Crust cool completely on a wire rack before serving. Dust with powdered sugar, if desired.