Preheat oven to 350°F (175°C). Grease or line a baking pan with parchment paper.
Cream butter and sugar until light and fluffy.
Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
In a separate bowl, whisk flour, baking powder, and salt.
Gradually add dry ingredients to the wet mixture and mix until just combined.
Spread batter evenly into the prepared pan.
Bake for 25–30 minutes or until lightly golden and a toothpick comes out clean.
Cool completely, then dust with powdered sugar if desired. Cut into bars and serve.