01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper or grease lightly.
02 - Combine yellow cake mix, melted butter, and 1 egg in a mixing bowl. Mix until a soft, cohesive dough forms.
03 - Press the dough evenly across the bottom of the prepared pan to create a uniform base layer.
04 - Beat softened cream cheese until completely smooth. Add eggs one at a time, mixing well after each. Blend in powdered sugar, lemon juice, lemon zest, and vanilla extract until fluffy and incorporated.
05 - Pour the lemon cream cheese mixture over the base, spreading evenly. Bake for 35 to 40 minutes until edges are set but center remains slightly jiggly. Avoid overbaking to maintain gooey texture.
06 - Let the cake cool completely in the pan before cutting into squares. Optionally dust with additional powdered sugar before serving.