Preheat the oven to 375 degrees.
Sift or whisk together the flour, salt and baking powder. Set the bowl aside.
In a stand mixer or with a hand mixer, cream together the butter and sugar.
In another bowl, whisk together the egg and vanilla.
Slowly add the egg and vanilla mix to the sugar and butter. Once it is incorporated, add in the flour mix slowly, about 1 cup at a time. Scrape the sides of the bowl as needed.
Roll the dough out on a lightly floured work surface. Divide it in 2 to make it easier to work with. If the dough feels too sticky, you can roll it between two pieces of parchment paper, but it shouldn't be that sticky. You can also flour the top of the dough a little too and dust the rolling pin. Just don't go overboard. Too much flour can impact the dough.
Roll the dough out to about ⅓ - ½ inch thick. Cut out the cookies using the cookie cutter. Place them on a cookie sheet lined with parchment paper. The parchment paper is important to keep the cookie bottoms from browning.
Use a measuring cup or spoon to light press down the center of each cookie. Place a dollop of the lemon curd in the center and smooth it out a little.
Bake the cookies for 10-11 minutes. When the time is done, remove them from the oven and use a spatula to immediately move them to a cooling rack.
Let cool for at least 30 minutes.
