Preheat oven to 350°F.
Finely grind almonds and walnuts separately in a food processor—just enough to make coarse meal, not nut butter.
Combine the ground nuts with coconut oil and salt. Press evenly into a 9½-inch pie plate.
Beat the egg whites until soft peaks form.
In another bowl, whisk egg yolks, pumpkin puree, spices, salt, vanilla, honey, and coconut milk.
Fold the beaten egg whites gently into the pumpkin mixture, then pour into the crust.
Bake for 20 minutes while you prepare the streusel.
Chop the walnuts and pecans coarsely, then mix with melted coconut oil, cinnamon, flaxseed, and honey until crumbly.
Remove pie from the oven and sprinkle the streusel evenly on top.
Bake another 30–35 minutes, until a knife inserted in the center comes out clean. Cover crust edges with foil if they brown too fast.
Cool completely, then refrigerate until ready to serve.