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

Toast the pecan pieces in a small pan over medium heat for 3–5 minutes until fragrant, then remove and let cool.

Peel, core, and chop the apples into small chunks. Set aside.

Cream together the softened butter and sugar using a hand mixer until fluffy. Add the egg and mix until fully incorporated.

Sift in the flour, baking powder, salt, and cinnamon into the wet mixture and mix gently until just combined.

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

Pour the batter into the prepared baking dish and spread evenly, then press down gently.

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

Allow to cool in the pan for 15–30 minutes before slicing into squares.