Preheat your oven to 350°F.
Grease a 9 x 13 baking dish with a non-stick spray and line it with parchment paper. Make sure you have overhangs on the sides of the baking dish.
Mix the sugar and ground cinnamon in a small bowl and set aside.
Beat your melted butter and sugars with a hand mixer. Then, add the eggs, vanilla extract, cinnamon, salt, and baking powder to the creamed butter and mix until creamy.
Stir in the flour. Combine everything with your electric mixer, then use a large spoon to mix the batter. It should be very thick.
Add the apples and mix into the batter.
Stir in the chopped pecans. You can use your hands to mix the batter thoroughly.
Transfer the batter to the prepared baking dish and even it out with an offset spatula.
Top the batter with your cinnamon-sugar mixture earlier.
Bake your apple cinnamon brownies for 45 minutes. Adjust the baking time as needed. You can insert a toothpick in the center of the brownies, and if it comes out clean, it’s done.
Remove the baking dish from the oven and allow it to cool before slicing.