1. Preheat oven to 350°F (175°C). Grease a 9×13-inch baking pan or line with parchment paper.

2. Bring eggs to room temperature if possible for best results.

3. In a large mixing bowl, combine entire box of yellow cake mix, pumpkin puree, eggs, oil, cinnamon, nutmeg, ginger, and cloves.

4. Beat with whisk or electric mixer on medium speed for 2-3 minutes until completely smooth with no dry cake mix pockets visible.

5. If using mix-ins like chocolate chips or nuts, fold in gently with spatula. Reserve handful to sprinkle on top.

6. Pour batter into prepared pan and spread evenly, reaching all corners.

7. Tap pan gently on counter 3-4 times to release air bubbles.

8. Sprinkle reserved mix-ins on top if desired.

9. Bake for 25-30 minutes until edges are set and toothpick inserted in center comes out with moist crumbs (not wet batter).

10. Don’t overbake—center may look slightly underdone but continues cooking after removal.

11. Remove from oven and cool in pan on wire rack for at least 20 minutes before cutting.

12. For cleanest cuts, cool completely (1 hour), then cut with sharp knife wiped clean between cuts.

13. If frosting, cool completely before applying cream cheese frosting.

14. For frosting: Beat softened cream cheese and butter until fluffy. Add powdered sugar and vanilla, beat until smooth. Spread over cooled bars.