There is nothing quite like the aroma of a plum cake baking in the oven.
Preheat the oven to 350F.
Lightly grease and 8-inch pan with butter.
Place the butter and sugar into a mixing bowl and beat with an electric mixer until creamy. Add the yogurt and beat in.
Stir the baking powder into the flour.
Add the flour mixture and buttermilk to the butter mixture, beating in alternating the two until combined.
Mix in the lemon peel.
Pour into the prepared pan.
Wash and pit the plums, then slice.
Arrange the plums into the batter, pressing some gently down and leave some at the top.
Sprinkle with the brown sugar and cinnamon.
Place into the preheated oven and bake 40 minutes or until a toothpick inserted in the center of the cake comes out clean.
Remove and place onto a cooling rack.
Let cool down to just warm before cutting and serving.