Step 1Cover the prunes with brandy and macerate overnight. The next day, strain the prunes, reserving the brandy. Cut 20 prunes in half; quarter the remaining 10.
Step 2Roll out the dough and place in a buttered 9-inch pie plate. Trim the edge, leaving one-fourth inch beyond the pie plate. Roll the edge of the dough up and on top of the edge of the plate. Do not crimp. Refrigerate.
Step 3Cut 6 tablespoons of butter into half-inch pieces and place in a heavy one-quart pot over medium-high heat until the butter foams and begins to brown. Remove from the heat, swirl the pot a few times and set aside to cool slightly.
Step 4Place the almonds in a food processor and grind until fine. Add all the flour, one-fourth cup plus 2 tablespoons sugar and all the salt. Pulse to combine and remove to a bowl.
Step 5Add the warm brown butter and, using your hands, toss and squeeze the topping until you have crumb- to walnut-size pieces. Add the oats and quartered prunes; toss together; set the streusel aside.
Step 6Peel, halve and core the pears; cut 10 halves in half again. Sprinkle with the lemon juice.
Step 7In a large heavy saute pan, heat 2 tablespoons butter and 3 tablespoons sugar over medium-high heat until bubbly. Add 5 pear halves (cut side down), 2 star anise and 2 pieces ginger. Swirl the pan so the butter and sugar coat the pears. Set the pan back on the burner to caramelize the butter and sugar. When the butter begins to brown, swirl the pan to incorporate the browned butter. (The pears should just begin to soften while the butter and sugar caramelizes.) Cook the pears until the cut surfaces are dark golden, about 12 minutes. If the butter browns too quickly, lower the heat.
Step 8Remove the pan from heat and add 3 tablespoons of the reserved brandy. Return the pan to the heat, gently swirl and reduce the liquid until a spoonful poured over a pear sticks slightly. Remove the pears to a plate, scraping the caramel sauce over them. Discard the star anise and ginger. Wash the pan and repeat steps 7 and 8 with the remaining 2 tablespoons butter, 3 tablespoons sugar, 2 star anise, 2 pieces ginger and 5 pear halves.
Step 9Heat the oven to 350 degrees. Place the quartered (raw) pears in a large mixing bowl and toss with the brown sugar, ground ginger and nutmeg. Add the caramelized pears, caramel sauce and halved prunes; toss together.
Step 10Remove the pie crust dough from the refrigerator and crimp the edge of the crust. Place the filling in the shell, and evenly distribute the streusel over the top. Bake 1 hour, 45 minutes, or until any liquid bubbling is a dark caramel color.