Preheat oven and butter pans:
Heat the oven to 350°F (175°C). Butter two 8x4" or 9x5" loaf pans.Whisk dry ingredients together:
In a medium bowl, combine flour, baking soda, baking powder, salt, cinnamon, and nutmeg with a whisk. Set aside.Beat oil and sugar:
In a stand mixer bowl fitted with a paddle attachment, beat oil and granulated sugar on medium speed until blended.Add eggs one by one:
Turn the mixer to low, then add eggs one by one, mixing briefly after each addition until combined.Stir in pears and vanilla:
Stir in chopped pears and vanilla until incorporated.Mix in dry ingredients:
With the mixer running on low, slowly add the dry mixture, mixing only until no dry streaks remain. Avoid overmixing.Divide batter into pans:
Split the batter equally between the two greased pans.Make and add streusel:
For the streusel: in a small bowl, stir together granulated sugar, brown sugar, flour, and cinnamon. Drizzle in vegetable oil 1 tablespoon at a time, working it with your fingers until it feels like wet sand. Distribute the streusel evenly over the two loaves.