Start by preparing and weighing all the ingredients needed.
First cut butter into small cubes. This makes combining butter with other ingredients easier. Leave to soften to room temperature (about 20 minutes).
Then, toast the walnuts in an oven preheated to 180 degree C for about 8 to 10 minutes until they are nicely brown. Toasting brings out the flavour of the nuts.
Let the walnuts cool and then finely chopped the walnuts.
Put the chopped walnuts in a shallow bowl and set aside.
Next, separate one egg into yolk and white.
Put the egg white in a large bowl and whisk until it's nice and frothy.
Pour it into another shallow bowl and set aside for later use.
In a separate bowl, whisk together the all-purpose flour and salt. And we're ready to make the cookies.
Start by making the cookie dough. Beat the softened butter in a stand mixer with a paddle attachment until nice, creamy and smooth.
Then, add in sugar and beat until its light and fluffy (2 - 3 minutes). This is to give it a lighter texture cookie.
Next, add in the egg yolk.
Also, add in vanilla extract and beat everything together.
Lastly, add in the flour mixture.
Beat the flour mixture until a batter is formed. Scape down the sides. And we're done with the cookie dough.
Then, as this batter is quite soft, put the cookie dough in a bowl, cover with cling wrap and chill in refrigerator for about half an hour. (Just to get it firm enough to roll easily).
When the cookie dough has been chilled, preheat oven to 180 degree C (350 degree F).
Line a baking sheet with parchment paper.
Using a tablespoon, weigh each dough to 15g and roll into balls. You will have about 20 balls. Weighing ensures the balls are of the same size and will bake evenly and at the same amount of time.
Then roll the dough ball in the whisked egg white. The egg white acts like a glue.
Next, roll the glued ball in the chopped walnut, to cover them so that the nuts will stick to the dough.
Put the rolled ball on the lined baking sheet. Continue to do the same for the rest of the dough balls. Evenly space them on the baking sheet.
Next, using your thumb or something round, make an indentation into the centre of each cookie dough.
Fill each indentation with the raspberry jam using a small spoon or a filled piping bag. Do not overfill, just a little above the indentation so it will not flow over the sides when baked.
Continue to pipe until all the cookies are filled with jam.
Then, bake in the preheated oven for 12 to 15 minutes until the edges of cookies are golden and the nuts have browned. Just touch the cookies and they should be firm when done.
Remove the baking sheet from oven to cool on wire rack for not more than 2 minutes.
Then transfer the thumbprint cookies to another cooling rack to cool completely. And we're done!
Enjoy these buttery soft yet crunchy cookies with a freshly brewed cup of coffee or tea. Certainly make a colourful and delightful addition to any cookie tray.
Make a batch of these impressive-looking jam-filled thumbprint cookies and wrap them up nicely as they make great Christmas gifts. As always, ENJOY!