Unless everyone in your family has dangerously high cholesterol levels, I really don't think making an egg yolk cake (all the above suggestions are good ones) once in a while will really hurt. Eating egg yolks occasionally won't raise your blood fat levels - it's how much cholesterol you consume over a period of time that does you harm. Of course, it pays to be careful, but every now and then shouldn't matter.
What does your doctor say?
You can freeze the yolks until you are ready to use them.
Also you can gift a cake or other baked goods to a friend or neighbor, donate to a bake sale, church dinner, lots of bingos sell food and homemake desserts and would be happy for your donation.