Cream your butter using an electric mixer until it becomes lighter in color for about 2 minutes. After that, add the sugar and mix again for another 2 minutes. Or mix it until the mixture becomes light and fluffy. Then, add the lemon zest. And make sure to beat it again until combined entirely.

Afterward, put the egg yolks one at a time while still beating. With that, ensure to beat the egg yolks after each addition. Then, mix in the vanilla extract.

After that, set your mixer in low. Then, put the flour and salt until the dough combines well. However, be careful not to over-mix.

Next, scrape out the cookie dough out of the bowl using a rubber spatula. Then, ensure to form the dough into a big flat disc. Afterward, wrap the dough using a plastic cling wrap and put it inside the chiller or fridge. Make sure to do this for about an hour. Or store it until it becomes firm.

Afterward, ensure to preheat your oven to 350 degrees Fahrenheit and line your two baking sheets with parchment paper. Then, divide your dough into two parts. Make sure to place one part in the chiller. And ensure to roll out the other part into 1/4-inch thick using a rolling pin.

After that, cut out as many Linzer cookies as you can using a 2-inch cookie cutter. In this regard, you can indeed use any shape of your choice. Because of that, keep the scraps of the cookie dough.

Next, repeat the process with the remaining dough, including the scraps you have saved earlier. Afterward, re-roll the dough to cut more.

Then, place your cookies in the lined baking sheets. And ensure that your cookies are one inch apart from each other. Keep in mind to cut out a small heart or hole. Likewise, any design you want from half of the cut-up cookie dough. If you do not have a small cookie cutter, you can use the round end of a pastry tip.

After that, place the cut-out cookies inside the chiller or refrigerator for about 15 minutes. Then bake the cookies for about 12 minutes. Or bake it until they become golden brown. Then, rotate the pans once throughout the baking process.

Once the cookies cook completely, take the cookies and leave them inside the baking sheets for about 5 minutes. With this, make sure to do it before moving them into a cooling wire rack. Also, let the cookies cool completely.

After the cookies cooled entirely, sift powdered sugar over the cookies that have holes in the center. Then, add a spoonful of raspberry jam to the cookies without holes. Because of this, ensure to spread the jam. Place the cookies with powdered sugar over the ones that have a jam. And make sure to press lightly to attach. Lastly, serve and enjoy!