Preheat the oven to 350 degrees.
In a small bowl, whisk together the 1 1/2 cup flour, 1/2 tsp baking soda, 1/4 tsp baking powder, 2 tsp cinnamon, and 1 tsp salt.
1/4 tsp baking powder, 1/2 tsp baking soda, 2 tsp cinnamon, 1 1/2 cup flour, 1 tsp salt
In an electric mixer, cream together the 3/4 cup unsalted butter and 1 1/2 cup brown sugar on medium speed until combined. Add the 2 eggs and mix on medium speed to combine.
1 1/2 cup brown sugar, 3/4 cup unsalted butter
Add the flour mixture into the butter mixture ΒΌ cup at a time, mixing to combine between each addition.
Line a brownie pan with parchment paper and pour in the batter.
In another bowl, whisk the 1 1/2 cups pecans, 2 eggs, 2/3 cup dark corn syrup, 2 tsp vanilla, 1/3 cup brown sugar, 1/4 cup butter, 1 tsp salt, 2 tsp cinnamon, and 1/2 tsp nutmeg until smooth. Pour the mixture over the blondie batter.
2 eggs, 1 1/2 cups pecans, 2 eggs, 2/3 cup dark corn syrup, 2 tsp vanilla, 1/3 cup brown sugar, 1/4 cup butter, 1 tsp salt, 1/2 tsp nutmeg, 2 tsp cinnamon
Cover the pan with tin foil and bake for 20 minutes. Remove the foil and bake for another 15 minutes or until the center of the blondies are set.
Cool for at least 10 minutes before serving.