Grooms cake vary by region. In the south, it's generally a chocolate cake decorated in either a masculine style or in something special to the groom like a Golf theme etc. I've noticed grooms cakes becoming more eloborate and a lot more fun. I agree tell the bride but ask her if she will touch base with the groom's mother because otherwise you have are in the middle.
Has anything changed? Your pans, your recipe, the humidity? Have you checked to see if the temp in the oven is correct? Buy an oven thermometer and see if your oven is correct. Mine is off 25 degrees. If yours has gotten off it may be cooking too slowly so your cake isn't rising enough.
Are you baking from scratch? Is your baking powder or soda old? That can effect rising as well.
How do you know it's not your powdered sugar?
I had this happen once and I let it sit over nigth and remixed it in the morning and it was better. Not 100%. I had already made a new batch for the customer but the "saved" batch was fine for experimenting and family.
Yep. I worked at Baskin Robbins as a kid and I was trying to figure out their fudge frosting they use on their ice cream pies...taste awesome but it is that commercial fudge stuff so I am happy to stick with my 2 ingredient yummy ganache:)
Just a heads up on the Strawberry cake. The other day I 1/2 the recipe and accidently added the full amount of baking soda (only 1/2 tsp for 1/2 box mix) and it was a huge mistake. It came out crazy salty. A quick google search told me that baking soda and acid result in salt. Strawberries are highly acidic. So just an FYI out there, be careful with adding too much baking soda when playing around with the density of a cake. 1/2 tsp was just perfect for a single box mix...
To clarify the person who said that's not OK to eat. Disco dust is plastic. I agree with Leah , you can find very pretty sparkling sugar colors and use a lot of it. I do not put disco dust on anything that someone will consume. Just because Elmers glue is non toxic does not mean I'll use it on a cake;)