Preheat the oven to 350 degrees F (176 degrees C) and get out a 9x13-inch pan. Line the pan with foil and grease it with Nonstick Cooking Spray (to taste).
Combine the All-Purpose Flour (2 cup), Baking Powder (1 teaspoon), Ground Cinnamon (1 teaspoon), Ground Nutmeg (1/2 teaspoon), and Salt (1/2 teaspoon) together in a bowl and whisk them together. Set the dry ingredients aside.
Get a large saucepan on the stove and melt the Butter (1 cup) in it. Whisk in the Dark Brown Sugar (2 cup) and keep whisking until it is dissolved and thick. Take it off the heat and let it cool for a few minutes.
Then whisk in the Egg (2) and Vanilla Extract (1 tablespoon). Whisk in the dry ingredients until you have a soft, sticky batter.
Spread the batter evenly in the prepared pan.
Bake for about 20 minutes. A toothpick inserted in the center should come out cleanly.
Let the tray cool completely.
While the tray cools, make the praline icing. Wash out the saucepan you used for the blondie batter and then get it back on the stove. Combine the Butter (8 tablespoon) and Dark Brown Sugar (1 cup) in it and let it come to a gentle boil over medium heat while you stir it constantly.
Pour in the Heavy Cream (1/3 cup) and stir it in, letting it come back up to a gentle boil for 5 minutes while you keep stirring.
Take it off the heat and let it cool for 15 minutes.
Stir in the Powdered Confectioners Sugar (2 cup) until you have a nice icing. Then stir in the Chopped Pecans (1 cup).
Working quickly before it sets, spread the icing evenly and smoothly on the cooled blondie layer. Set the tray in the refrigerator to completely set for 2 hours.
Cut into 20 even squares and serve!