Spread the 150 g (5 oz) almonds on a baking sheet and place in a preheated oven, 180°C (350°F), Gas Mark 4, for 7–10 minutes until lightly browned. Leave to cool.
Place the cooled almonds in a food processor or blender and whizz until fine. Pulse in the flour, 100 g (3½ oz) of the icing sugar, the cinnamon and a pinch of salt, then add the almond extract and butter and process until the mixture just comes together to form a dough. Wrap in clingfilm and chill for 30 minutes.
Using your hands, roll the dough into 24 balls. Place on one or two baking sheets lined with nonstick baking paper, spaced apart, then press 1 blanched almond into each one.
Bake in the preheated oven for 20 minutes until lightly browned around the edges. Transfer to a wire rack and leave to cool.
Sift the remaining icing sugar over the cookies and serve with coffee. They will keep for up to 3 days in an airtight container.