How long do you bake 3 boxes of cake mix in a half sheet pan?

I can't give you a specific baking time for 3 boxes of cake mix in a half sheet pan. Here's why:

* Cake mix brands and recipes vary: Each cake mix has its own instructions, and baking times can change depending on the recipe.

* Pan size and shape: A half sheet pan can have different dimensions. The size impacts baking time.

* Oven temperature: Different ovens have slight temperature variations.

* Altitude: Higher altitudes require adjustments to baking times.

Here's how to determine the baking time:

1. Check the box instructions: The back of each cake mix box will have the baking time for a standard cake pan.

2. Adjust for a larger pan: Since you're using a larger pan, you'll likely need to bake it longer. Use the box instructions as a starting point and check for doneness earlier than the recommended time.

3. Use a toothpick test: Insert a toothpick into the center of the cake. If it comes out clean, it's done.

Tips for success:

* Preheat your oven: Make sure your oven is preheated to the temperature specified on the cake mix box.

* Use a toothpick test: Check the cake for doneness several times throughout baking.

* Let it cool: Allow the cake to cool completely in the pan before frosting.

I hope this helps! Happy baking!