Preheat the oven to 175°C (350°F), fan-assisted. Line two or more baking trays with parchment paper.

Place the almonds in a blender or food processor, together with 2 tablespoons of the flour. Process at high speed until coarsely ground.

Place the butter, sugar and salt in the bowl of a stand mixer and beat until light and fluffy. Add the egg yolks and vanilla and continue mixing briefly, until well incorporated.

Add the flour and cinnamon and mix until a soft cookie dough forms.

Lightly beat the egg whites in a bowl, just enough to loosen them. Place the coarsely ground almonds in a separate bowl.

Take small portions of dough, approximately the size of a walnut, and roll them into balls. Dip each ball into the egg white and, using a fork, transfer it to the bowl of ground almonds. Gently roll it around until evenly coated on all sides.

Using your finger, make a small indentation in the centre of each ball. Arrange the cookies on the prepared baking trays and gently flatten them with the palm of your hand.

Fill each indentation with approximately ¼ teaspoon of strawberry jam. Continue with the remaining dough until all the cookies have been shaped and filled.

Bake the cookies for approximately 20 minutes. Halfway through the baking time, rotate the tray 180 degrees to ensure even browning.

Once the cookies are lightly golden, remove them from the oven and let them rest for a few minutes. Transfer them to a wire rack and allow them to cool completely.

Once completely cool, store the cookies in an airtight container or cookie tin.