Heat oven to 425 degrees. In the bowl of a food processor fitted with the metal blade, process almonds, flour, brown sugar, 2 tablespoons granulated sugar, cinnamon, nutmeg, and 1/8 teaspoon salt until nuts are finely chopped, about nine 1-second pulses. Drizzle butter over mixture and pulse until it resembles crumbly wet sand, about five 1-second pulses; set aside.
In a large bowl, whisk together remaining 2 tablespoons granulated sugar, cornstarch, lemon juice, and pinch of salt. Peel pears, then half (from stem to blossom end). Use a melon baller to remove core. Quarter each half lengthwise and then cut each piece in half crosswise for eight pieces (pieces should be about 1 1/2 inches). Gently toss pears with sugar mixture and transfer to 8-inch-square baking dish.
Sprinkle topping evenly over fruit, breaking up any large chunks. Bake until fruit is bubbling around edges and topping is deep golden brown, 27 to 32 minutes. Cool on wire rack until warm, at least 15 minutes, and serve.