Upside-down Red Plum Cake

Last time we traveled to Kenya, I came home with a bag of red plums.  Before the years we lived in Kenya, I always wondered why the most common flavor of jam in the Ugandan supermarkets was "red plum", but then I discovered that they grow actually in Kenya.  Mystery solved.

After eating some of the plums fresh, I decided that I should make some kind of fun dessert with the rest.  I decided on an upside-down cake because it's always been a favorite of mine.  I combined several different recipes and came up with this:

Melt 4 Tbs. butter in an 11" cast iron skillet.  Mix 6 Tbs. brown sugar with the butter, then slice your plums in half and place them, cut side down on top of the butter/sugar to cover the skillet.  I used around 15 or so (they were pretty small).

For the cake:
1/2 c. softened butter
2/3 c. brown sugar
1 egg
1 teaspoon vanilla
2/3 c. plain yogurt
2/3 c. flour
2/3 c. whole wheat flour
1 teaspoon baking powder
1/4 teaspoon baking soda
1/4 teaspoon salt
1/4 teaspoon cinnamon

Mix everything together well, then pour it on top of the plums.  Bake at 350F for 25-35 minutes.  Let it cool in the pan for 10-15 minutes, then put a plate on top of the skillet and flip the cake over onto it.

It was really good and very beautiful to look at.  The strange thing, though, was that the plums seemed to turn my teeth kind of grey each time I'd eat a piece of cake.  I had to brush my teeth right away afterward to get rid of the color.