In a small bowl, whisk together the flour and salt and set aside.
In a large mixing bowl, beat together the butter and the powdered sugar with a hand mixer until it’s reached a light and fluffy texture.
Using an egg yolk separator, strain the eggs separately into a different bowl. Add in one egg white and mix it in until it’s thoroughly incorporated. Next, add in one egg yolk, whisk, then add in the second egg yolk and mix thoroughly.
Once the eggs have been added, add in the vanilla and the lemon flavoring oil. Only add in a few drops of the oil. Feel free to adjust this as needed but when I made this recipe, I felt two drops added just the right amount of lemon flavor to the cookies. Mix together on medium speed until both of the ingredients have been mixed into the dough.
Next, add in the dry ingredients (the flour and salt), and mix together just until it’s combined with a large wooden spoon or spatula. DO NOT OVERMIX THIS. You will only want to mix the ingredients until you no longer see the flour.
Spoon the dough onto parchment paper and either wrap it up into a ball or flatten it between two pieces of parchment paper and place it in the fridge for up to four hours or even overnight.
When the dough has chilled, preheat the oven to 350 degrees.
Prepare your baking sheet with either parchment paper or a silicone baking mat.
Next, prepare the area where you will be rolling out the dough and lightly flour it.
Remove the dough from the fridge, divide it into two halves and place the one half back into the refrigerator and place the other half on the floured surface.
Roll out the dough until you get it to a thickness of about ¼ of an inch thick.
Dip the cookie cutter, without the interchangeable insert, into a little bit of flour, and then into your dough. These will be your bottom cookies.
Next, re-roll any of the scraps of dough and continue the process making additional cookie bottoms.
When you are done making the bottoms, get the remaining dough out of the fridge and roll that out into ¼ of an inch thickness. Then add in the interchange shape that you would like for the cookies to be and cut those shapes out. These will be the tops of your cookies.
Place the cookies on your prepared cookie sheets and bake at 350 degrees for 10 – 12 minutes or until the edges are light golden brown.
Remove the pans from the oven and let them cool for 10 minutes before removing the cookies. After 10 minutes, remove the cookies and place them on wire racks to finish cooling.
Once they have completely cooled, place the wire racks with the tops of the cookies on them over parchment paper and put the powdered sugar into a shaker or shifter. Shift the powdered sugar and then lightly shake the powdered sugar over the tops of the cookies.
Next, it’s time to assemble the cookies! Add 1/8 teaspoon of jam onto the bottom cookie and spread it out with a knife. Then add the top cookie and enjoy!