In a liquid measuring cup, whisk together the milk and cream of tartar. Set aside to thicken, about 20 minutes.
Preheat oven to 350 degrees and prepare a 10-inch bundt pan with cooking spray.
In a large mixing bowl, whisk together the flour, baking soda and salt. Separately, beat the remaining wet cake ingredients (including the milk mixture) with a hand mixer. Fold the wet ingredients into the dry, and incorporate.
For the spiced pecan layer, combine the brown sugar, chopped pecans, and pumpkin pie spices in a small bowl and set aside.
Spoon half of the batter into the prepared bundt pan and sprinkle with the spiced pecan mixture. Add the other half of the batter on top.
Bake for 45-50 minutes, or until golden brown with surface cracks beginning to form.
Allow the cake to cool for 15 minutes before turning out of the pan. Meanwhile, whisk together the ingredients for the maple glaze.
Drizzle the glaze over the cake and garnish with chopped pecans before slicing to serve.