Preheat the oven to 180°C (350°F), Gas Mark 4.
Finely chop the almonds in a blender.
Tip the almonds into a mixing bowl and mix in two-thirds of the icing sugar, the baking powder, butter, egg yolks and whole eggs, and lemon rind.
Add the orange-flower water to make a dough. Using wetted hands, form into balls about the size of a walnut.
Tip the remaining icing sugar onto a plate and roll each ball in it until coated. Place on an oiled baking sheet, spaced well apart. Press an almond into the top of each one and transfer to the oven. Cook for 15 minutes.