I find the recipe for my butter cake too sweet. Is it okay to just lessen the amount of sugar in the recipe? Will it affect the outcome of my cake?

Yes you can lessen the amount of sugar in your recipe but it will be a little firmer in texture and a bit drier. A cake high in sugar will fall apart easily because it is more tender but is also has a harder mouth feel. Sugar also helps retain moisture in baked cake.

Why is it that in some cake recipes it requires both whole eggs and egg yolks?

The advantage of using extra egg yolks is for superior flavor and a more golden color. The crust also browns more because the yolk is higher in protein and contains fat.

Last week I baked an angel cake for my mother-in-law. After baking I noticed that the cake shrank. What caused this and how can I prevent this from happening?

One of the most common reasons why cakes shrink is forgetting to turn the cake pans over after removing them from the oven. Allowing cakes to cool upside down prevents shrinkage. Also, if the cake was removed early from the oven, the weak structure of the interior of the cake may cause shrinkage. Over baking it will cause drying, and cakes will shrink as they cool.