01 -
Preheat the oven to 175°C and line an 20×20 cm baking pan with parchment paper.
02 -
Beat the softened butter with granulated sugar and brown sugar until light and fluffy.
03 -
Add the egg and vanilla extract to the creamed mixture and mix until fully combined.
04 -
Whisk together the flour, baking powder, salt, cinnamon, and nutmeg in a separate bowl.
05 -
Gradually fold the dry ingredients into the wet mixture until just combined to avoid overmixing.
06 -
Gently fold the finely diced apple into the batter ensuring even distribution.
07 -
Spread the batter evenly into the prepared baking pan.
08 -
Combine 25 grams granulated sugar with 1 teaspoon ground cinnamon and sprinkle evenly over the batter.
09 -
Bake for 25 to 30 minutes, or until the edges are golden brown and a toothpick inserted in the center comes out clean.
10 -
Allow to cool completely in the pan before cutting into bars to ensure clean slices.