Pre heat the oven to 180c/350f/Gas 4. Combine the butter and sugar and beat until creamy. Add the egg yolk and a splash of vanilla essence, then stir in the almonds and flour. Chill. Slice the plum loaf and place on a greased baking sheet. Cook for 10 mins in oven. Place a spoonful of almond mixture onto the slices, then press 3-4 cherries onto the top. Bake for another 10 mins or until golden. Cool slightly, then dust with icing sugar. Serve with cream or ice cream.