Preheat your oven to 350°F (175°C) and prepare an 8x8-inch baking dish by greasing it or lining it with parchment.

In a medium skillet, toast pecan pieces over medium heat for about 5-7 minutes, then remove and let cool.

Peel, core, and chop 1 cup of apples into 1/2-inch chunks, set aside.

In a large bowl, cream together 1/2 cup softened butter and 1 cup sugar until light and fluffy.

Add an egg to the mixture and beat until fully incorporated.

In a separate bowl, whisk together 1 cup of flour, 1 teaspoon baking powder, a pinch of salt, and 1 teaspoon cinnamon; then gradually combine with the wet mixture.

Fold in the apple chunks and toasted pecans gently, ensuring even distribution.

Pour the batter into the prepared baking dish and bake for 30-40 minutes until the top is set.

Allow the brownies to cool in the pan for at least 15 minutes before slicing and serving.