Preheat oven to 350 degrees F. Set one rack in the lowest position and the other in the middle of the oven. Place a foil-lined baking sheet on the lowest rack.

Rub sweet potatoes with canola oil. With a fork, pierce each potato 5 to 6 times in different places around the potato. Place the potatoes directly on the upper rack and bake until tender when pierced with a fork, about 1 hour. Remove from the oven and place on a cutting board to cool slightly.

Cut each potato in half lengthwise. Gently scoop out the flesh, leaving a ¼-inch layer of potato. Place 8 of the potato shells on a large baking sheet and discard the remaining shells. Place the sweet potato flesh in a large saucepan set over medium heat. Using a whisk, mash and vigorously stir the sweet potato until slightly dry, about 5 minutes. Add butter, maple syrup, cinnamon, chipotle chile powder, and salt. Whisk until the mixture is smooth.

Evenly divide the sweet potato mixture between the shells.

Melt butter in a large skillet set over medium heat. Add pecans, chipotle chile powder, and sugar to the skillet and cook, stirring, until the sugar begins to caramelize and the pecans are coated with the sauce, 4 to 5 minutes. Make sure the pecans do not burn. Spread the pecans on a baking sheet lined with parchment paper, sprinkle with salt, and cool.

In a medium bowl, combine flour, brown sugar, chopped pecans, butter, and salt. Using your fingers, mix the ingredients together until combined.

Sprinkle the streusel mixture evenly over the mashed sweet potatoes. Bake until the streusel mixture is melted together and beginning to bubble, about 15 minutes. Serve.