Place soft butter in a medium-size mixing bowl. Stir with a wooden spoon or sturdy spatula until nice and smooth.
Add powdered sugar and vanilla. Mix together by hand for about 30 seconds until well blended.
Add the flour and cornstarch. Stir until dry ingredients are incorporated. The dough will be a little shaggy, but will start to come together.
Turn the dough out onto a floured work surface and gather into a ball. Knead 5-6 times until smooth and all the small pieces are worked in. If the dough seems sticky, knead it again with a tablespoon of extra flour on your work surface.
Divide the dough into two portions. Form each portion into a ball again and flatten it with your hand to form a flat disk. Turn the disks to coat both sides with flour. Set one portion aside.
Roll out the dough to an approximate ¼-inch thickness (see Café Tips above in the post). Move the dough several times as you’re rolling it out so there’s always a thin layer of flour beneath your dough. Also, keep your rolling pin, lightly dusted with flour.
With a scalloped, round cookie cutter, cut out circles of dough and transfer them to a sheet pan using a thin, metal spatula, leaving 2 inches between each cookie.
Use a mini round cookie cutter, a large pastry tip or any round hollow utensil that’s ½ -¾-inch in diameter (I use my apple corer tool) to cut out the center of each circle, forming a “wreath”.
Re-roll scraps as many times as needed to use up the dough. Repeat with the second portion of dough.
Place cutouts in the refrigerator, uncovered, for at least one hour or up to 24 hours.