Melt butter and let cool slightly. In a large bowl beat one egg with the honey. Add the cooled butter and whisk until combined. Add the almond flour and a pinch of salt and beat until fully incorporated.
Butter or lightly grease 6 small shallow pie or gratin dishes and place the slices of plums inside in concentric circles. Cover with the frangipane batter and top each with a few sliced almonds.
Bake for 20 minutes or until golden around the edges.
Let cool on wire rack and serve slightly warm or at room temperature.
Recipe by OPSD Il gustoso food blog at https://www.opsd.it/frangipane-prugne/