Roll, Cut, and Chill the Bottom Cookies. Preheat the oven to 350° F. Line two large baking sheets with parchment paper. Remove the dough from the refrigerator. Clear your counter and lay down a large piece of parchment paper. Lightly dust the parchment paper with a few tablespoons of gluten-free flour, and add a sprinkle of flour on top of the dough. Roll the dough out to about ¼” thick. If the dough starts to stick to the parchment, dust the top and bottom of the dough with a little more gluten-free flour. Periodically lift the dough to make sure it's not sticking to the parchment paper. If it becomes too sticky and the butter starts to melt, quickly gather the dough into a ball, and start the process over. If the dough is no longer workable, try chilling it again for 30 minutes. Using a 2.25 x 2.25 x 2-inch fluted cookie cutter, cut out the bottom half of the cookies. With an offset spatula, carefully transfer the cookie bottoms to one of the lined baking trays, placing them about ½-inch apart. Place the baking sheet in the refrigerator for 10 minutes to chill.
Bake the Bottom Cookies. Remove the cookies from the refrigerator and bake for 10 minutes, just until the bottoms and edges are slightly brown.
Cool and Repeat. Remove the tray from the oven, and allow the cookies to cool for 5-10 minutes before transferring to a wire rack to cool. Combine the excess dough scraps, roll them out again, and cut out cookies. Make sure to not use a hot sheet tray to bake them or they will spread out! Repeat this process until all the dough is used from the first disc.
Roll, Cut, and Chill the Top Cookies. Add the detachable heart center to your linzer cookie cutter. Repeat the rolling out process with the second disc of dough. Once the dough is rolled out, use the cookie cutter to cut out the top half of the cookies. The center heart will push out of the scalloped top, leaving a doughnut hole appearance. Transfer the cookie tops and cut-out hearts to a lined baking tray, about ½-inch apart, then into the refrigerator for 10 minutes to chill.
Bake the Top Cookies. Remove the cookies from the refrigerator and bake for 10 minutes, just until the bottoms and edges are slightly brown. Repeat the process of rolling, baking, and cooling the cookies.