Plum Upside Down Cake
1 1/4 stick butter , softened
1/4 cup plus 2 tablespoons brown sugar, firmly packed
4 plums, pitted and sliced
5 tablespoons buttermilk OR 4 tablespoons milk plus 2 teaspoons milk and 1 teaspoon lemon juice
3/4 cup cake flour
1/2 teaspoon baking powder
1/8 teaspoon baking soda
1/4 teaspoon cinnamon
1/2 cup granulated sugar
Zest of 1/2 an orange
1 teaspoon vanilla extract
Preheat oven to 350 degrees F. Butter the insides of the ramekins.
Melt 3/4 stick of the butter in medium saucepan over medium heat. Add brown sugar and whisk until smooth. Pour into the bottoms of the buttered ramekins, dividing the sugar butter sauce evenly among them. Arrange a layer of plum slices at the bottom of each ramekin.
In a separate bowl, vigorously whisk together the cake flour, baking powder, baking soda, cinnamon and salt.
Use an electric mixer to beat together the remaining 1/2 stick butter with the granulated sugar and orange zest. Add the eggs and vanilla, mix to combine. Alternately add the dry flour mixture and the buttermilk mixture to the batter.
Divide the batter among the ramekins. Place the ramekins on a rimmed baking sheet and put in the oven on the middle rack. Bake at 350 degrees F for 35 to 40 minutes, until cakes are firm to the touch, and a toothpick or skewer inserted in the center does not come out with raw batter on it. Turn the baking sheet around half-way through the baking to ensure an even baking for all the cakes.
Remove from oven and let cool on a rack until no longer hot to the touch. Run a paring knife around the edges of the ramekins. Invert onto a plate and gently lift off of the plate. Serve alone or with whipped cream or vanilla ice cream.