Lemon Plum Cake
Rinse the plums, remove the pits and chop finely.
Beat the softened butter with sugar until creamy.
Add the eggs one at a time. Stir in the flour, baking powder, salt, lemon zest, flavoring, and lemon juice together with the plums.
Pour the batter into a buttered loaf pan, sprinkle with the remaining sugar and bake in a preheated oven at 400°F for about 1 hour. Switch off the oven and let the cake sit for 15 minutes in the hot oven, then remove from the oven. Allow the cake to cool slightly, then remove from the pan and cool on a wire rack.
Allow the cake to rest overnight, then slice and serve.