Step 1

Cream together the butter and sugar until creamy and completely combined.

Step 2

Add in the egg yolks, beat until combined.Beat in the flour until completely mixed in.

Step 3

Chill the dough for an hour in the fridge.

Step 4

Preheat your oven to 325 °F.

Step 5

Roll about 2 teaspoons of dough into a ball, then dip into the lightly beaten egg whites then roll in the walnuts, then place onto a parchment lined baking sheet. Repeat until the dough is all used.

Step 6

When the cookies are all on the parchment lined cookie sheet, press a well in the center of each ball prior to baking using your thumb, of course!

Step 7

Bake in the preheated oven for 10 minutes, then open the oven and re-press the wells using the handle of a wooden spoon to gently indent the cookies again. While the cookies are still on cookie sheets fill the wells with the raspberry jam. Return to the oven.

Step 8

Continue baking another 8 minutes until golden.

Step 9

Remove from the oven and move to wire cooling racks and let cool completely on the sheets.