Preheat the oven to 350 degrees F. Spread the pecans on a baking sheet; bake until toasted, 5 to 7 minutes. Let cool, then chop. Reduce the oven temperature to 200 degrees F.
Whisk the flour, sugar, salt, baking powder and baking soda in a large bowl. Whisk the egg, milk, buttermilk and vanilla in a separate bowl until combined. Stir the egg mixture, melted butter and shortening into the dry ingredients until just combined. (The batter will be lumpy.)
Preheat a waffle iron and brush with melted butter. Ladle some batter into the iron (about 1/2 cup, depending on your waffle iron); sprinkle with 2 tablespoons toasted pecans. Cook until golden brown, then transfer the waffle to a baking sheet and keep warm in the oven. Repeat with the remaining batter. Top the waffles with butter and maple syrup.
Photograph by Kang Kim
Recipe courtesy Food Network Magazine