On cakes nine inches in diameter or greater, or more than two inches deep definitely use a heating core.
- Grease the inside and outside of the heating core, as you did your cake pan.
- Fill the pan with batter.
- Place the heating core in the center of the pan. Fill with batter.
- Remove heating core after cake has cooled.
- Fill the hole with cake from the center of the heating core.
- Decorate as usual.
Adjust the baking time
Unfortunately we can't be there with you when you are baking your cake. So, figuring out the timing is a little harder. There are so many factors that affect baking time (oven type, recipe, altitude, etc), so we can't give you one answer. You will need to keep an eye on your first cakes and and check for doneness throughout the baking cycle and documenting for future use in your oven.
Remember keep it Slow and Low!
No matter what the recipe says, adjust your temperature down to 300F when baking in a four inch deep pan.