Preheat the oven to 350 degrees.
Toast the pecans on a large baking sheet for 8-10 minutes, stirring upon occasion, until deeper brown and fragrant.
Place the bread cubes in a 9x13 baking pan that has been treated with cooking spray or butter.
Whisk together the pumpkin custard ingredients in a mixing bowl and then pour over the bread cubes. Stir to ensure the bread cubes are coated with the custard and let sit for 20-30 minutes.
For the streusel, stir together HALF of the chopped pecans, the brown sugar, flour, salt, and cinnamon. Cut the butter into the dry ingredients until the mixture resembles large crumbs.
Sprinkle the streusel crumbles evenly over the top of the bread cubes and custard.
Bake COVERED with foil for 30 minutes.
Bake UNCOVERED for an additional 10-15 minutes or until a knife inserted in the center comes out clean.
Cool for 20-30 minutes.
Cream the frosting ingredients together with a mixer until smooth.
Drizzle or pipe frosting in an irregular pattern over the bread pudding and serve warm.
Sprinkle with the top of the bread pudding with the remaining toasted pecans.