Preheat & Prep: Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking pan with non-stick spray or line with parchment paper.
Make the Crust: In a large bowl, mix together the dry yellow cake mix, melted butter, and 1 egg until a thick dough forms.
Press into Pan: Evenly press the dough mixture into the bottom of the prepared baking pan. Set aside.
Whip Cream Cheese: In a separate large bowl, use an electric mixer to beat the softened cream cheese until completely smooth and free of lumps.
Add Wet Ingredients: Beat in the remaining 2 eggs and the vanilla extract until fully combined.
Incorporate Sugar: Gradually mix in the powdered sugar until the topping is smooth and glossy.
Layer & Bake: Pour the cream cheese mixture evenly over the prepared crust. Bake for 40-45 minutes. The edges should be golden, but the center should still have a slight jiggle.
Cool completely: Remove from the oven and let cool completely on a wire rack. For the best texture and clean slices, chill in the refrigerator for at least 2 hours before cutting. Dust with additional powdered sugar before serving, if desired.