Preheat oven to 350°F (175°C). Grease a 9x13-inch pan, including the corners.
Mix cake mix, melted butter, and 1 egg in a bowl until it forms a soft dough.
Press the dough evenly into the bottom of the prepared pan using your hands or a spoon.
Beat softened cream cheese until smooth and fluffy.
Mix in 2 eggs, then gradually add powdered sugar, stirring until smooth and glossy.
Pour the cream cheese mixture over the base and spread to the edges.
Bake for 30–35 minutes, until golden and slightly cracked on top but still a bit jiggly in the center.
Cool completely in the pan, then cut into bars. Dust with powdered sugar if desired.