Preheat your oven to 160°C (320°F) and line two baking sheets with parchment paper.

In a large bowl, combine the almond flour, caster sugar, lemon zest, and salt, mixing well to distribute the zest evenly.

In a separate bowl, whisk the egg whites until frothy but not stiff, then add the almond extract.

Pour the egg white mixture into the dry ingredients and mix until a sticky dough forms.

Place the 40g icing sugar in a shallow bowl for rolling the cookies.

Using damp hands, roll tablespoon-sized portions of dough into balls, then roll each ball generously in icing sugar.

Place the cookies on prepared baking sheets, spacing them 5cm apart, and gently flatten each slightly with your fingertips.

Bake for 12-14 minutes until the tops are cracked and pale golden but the centres remain soft.

Allow cookies to cool on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.

For the glaze, simmer the Prosecco in a small saucepan over medium heat for 3-4 minutes until reduced by half.

Remove from heat and whisk in the 150g icing sugar and lemon juice until smooth and glossy.

Drizzle the Prosecco glaze over the cooled cookies using a spoon or piping bag, then allow to set for 15 minutes before serving.