Add the butter and sugar to the bowl of a stand mixer fitted with the paddle attachment. Beat on high for 5 minutes, scraping down the sides of the bowl periodically.

Meanwhile, in a separate bowl, sift together the flour, baking powder, and salt.

Add the egg yolks and vanilla extract to the butter mixture and beat at medium speed for another 2 minutes.

Add the dry ingredients to the butter mixture. Beat to incorporate.

Wrap 1/4 of the dough in parchment paper and the remaining dough in a separate piece of parchment paper. With the larger piece of dough, gently press it into an 8-inch round disk. Place the smaller piece of dough in the freezer for 2 hours (or until hard) and the larger one in the refrigerator for at least 30 minutes.

Once the dough is ready, set a rack in the center of the oven. Preheat the oven to 350 degrees F.

Remove the dough from the refrigerator. Cut two large pieces of parchment paper and lightly flour each side of the disk. Using a rolling pin, roll out the dough between the two sheets of parchment paper until it is 13 by 9 inches.

Transfer the dough to a 13 by 9 inch baking dish. Even out the dough across the pan by pressing down gently with your fingers.

Bake in the oven for 20 minutes or until the shortbread is light brown. At this point, remove from the oven and let cool.

Once it has cooled, spread the raspberry jam evenly over the shortbread.

Remove the dough from the freezer and shred the dough using a grater. Sprinkle the grated dough over the raspberry jam. Bake in the oven for 20 to 25 minutes, or until the top is lightly browned.

Remove the baking pan and let cool completely.

Once they have cooled, sift the confectioners’ sugar over the top. Cut into 9 bars (or smaller if preferred).