Preheat your oven to 350°F (175°C). Prepare your baking pan by greasing it or lining it with parchment paper.

In a large mixing bowl, cream together softened butter and brown sugar until light and fluffy, about 3-5 minutes.

Add the eggs one at a time, beating well after each addition until fully incorporated.

Stir in the pure vanilla extract evenly throughout the batter.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.

Gradually add the dry mixture to the wet ingredients, mixing gently until just combined.

Fold in the chopped apples, ensuring they are evenly distributed.

Pour the batter into the prepared baking pan and smooth the top.

Bake for 25-30 minutes or until a toothpick inserted comes out clean.

Let the cake cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.