Preheat oven to 350°F. Grease the 9×9 pan.
Mix the butter, sugar, and eggs in a large bowl.
Beat in the flour, baking soda, and salt.
Stir in the drained pineapple.
Spread the mixture evenly into the greased pan.
Bake for 28–33 minutes, until the top is lightly golden and a toothpick comes out clean.
Let cool for at least 10 minutes.
Cut with a plastic knife once fully cooled, and dust with powdered sugar.