1. **Preheat:** Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch baking pan with cooking spray or butter.

2. **Make the Crust:** In a large bowl, combine the dry yellow cake mix, the melted butter, and 1 egg. Mix by hand or with an electric mixer until a thick, sticky dough forms.

3. **Press:** Dump the dough into the prepared baking pan. Using your hands or the back of a measuring cup, press the dough evenly into the bottom of the pan to form the crust.

4. **Make the Filling:** In a separate medium bowl (or cleaned mixer bowl), beat the softened cream cheese until completely smooth and fluffy. (Lumps in the cheese will show in the final cake, so take your time here!).

5. **Add Wet Ingredients:** Beat in the 2 remaining eggs and the vanilla extract until combined.

6. **Add Sugar:** Gradually add the powdered sugar, about 1 cup at a time, beating on low speed until fully incorporated and smooth.

7. **Assemble:** Pour the gooey cream cheese batter over the cake crust layer. Use a spatula to spread it out to the edges.

8. **Bake:** Bake for 35–40 minutes. **Do not overbake.** The edges should be golden brown and firm, but the center should still be jiggly (it will firm up as it cools).

9. **Cool:** Remove from the oven and let the cake cool completely in the pan on a wire rack. It needs time to set.

10. **Serve:** Once cool, dust the top generously with extra powdered sugar. Slice into small squares (it is very rich!) and serve.