Below is my SMBC recipe. My 6 yr old ds says that it tastes too buttery (as does my dh), but my other two kids love it. I have added powdered sugar to the recipe to lessen the buttery taste (which makes it a dream to work with as well - adds stability).
Comments? Suggestions? I find that SMBC is not a crowd pleaser - you either like it or find it too buttery and it seems that there is always someone complaining that it's too buttery, which quite frankly usually makes me want to hit them with a spatula - I'm kidding - a little ;)
My egg whites are measured in cups because I use pasteurized egg whites - I know lots of people here don't like them, but mine whip up really firmly.
1.5 cup of egg whites (roughly 12 egg whites)
2 1/4 cups of sugar
1/8 tsp cream of tartar
6 sticks of room-temperature butter
1.5 tbsp pure vanilla extract
1 cup powdered sugar (added at the end)