6 tbsp Unsalted Butter, plus extra for greasing the tin
Powdered Sugar, to serve
Preheat the oven to 400°F, Lightly grease a muffin tin.
Melt the butter in a small pan then set aside for a few minutes to cool. Next, prepare the plums. Open the can and remove several plums. Slice each in half and remove pit, then slice plum halves into thin strips.
In a large bowl, mix together the almonds, salt, flour and sugar, then add the almond extract and egg whites and whisk well until combined.
Gradually pour in the melted butter, mixing constantly until you have a smooth mixture with the consistency of pancake batter.
Divide the mixture between nine muffin cups, then arrange the strips of plum across the top of each – you will need 2-3 pieces per cake.
Bake for 8 minutes, then turn the heat down to 325F and bake for .a further 6–10 minutes. Keep an eye on them, as you want them to be golden around the edges and just set on top.
When they are done, the cakes should spring back slightly when pressed. Leave them to cool for 15 minutes before removing from the tin.