Preheat your oven to 350°F (175°C). Grease an 8x8-inch baking dish with baking spray or line with parchment paper.

In a small skillet over low heat, toast the pecan pieces for 5-7 minutes or until fragrant and golden brown. Allow to cool.

Peel, core, and chop the apples into ½-inch chunks. Set aside.

In a large mixing bowl, cream together the butter and sugar using an electric mixer for 2-3 minutes until fluffy. Add the egg and mix well.

Sprinkle in the flour, baking powder, salt, and cinnamon; gently mix until just combined.

Fold in the chopped apples and toasted pecans until evenly distributed.

Pour the batter into the prepared baking dish and smooth the top with a spatula.

Bake for 30-40 minutes until the edges are golden and a toothpick comes out with moist crumbs.

Let the brownies cool in the pan for 15-30 minutes before slicing.