These classic cookies are a favorite around the holidays. They are made with a simple sugar cookie dough and filled with the preserves of jam of your choice.
1 c. unsalted butter, at room temperature
1/3 c. sugar
1/3 c. light brown sugar, tightly packed
1 large egg yolk
3/4 t. vanilla extract
2 1/4 c. all-purpose flour
2 t. corn starch
1/2 t. salt
1/2 c. sugar, for rolling
1/3 c. preserves or jam, of choice
Place butter in the bowl of a stand mixer or use a large bowl and an electric hand mixer; beat until creamy. Scrape down the sides of the bowl; add sugars; beat, gradually increasing mixer speed to medium-high until ingredients are well-combined, about 30-60 seconds. Add egg yolk and vanilla extract; beat well.
In a separate bowl, whisk together flour, corn starch, and salt.
With the mixer on low speed, gradually add the flour mixture to the wet ingredients until completely combined. The dough will seem very dry and crumbly, so be sure to pause occasionally to scrape the sides and bottom of the bowl. If it starts to strain the mixer, use your hands to finish working the dough together.
Scoop cookie dough into 1 T. sized balls; roll very well so that the dough is round and there are no cracks/seams in the cookie dough. This will help keep your thumbprints from cracking.
Roll the dough balls in granulated sugar; place on a wax-paper covered plate or a small cookie sheet. Use your thumb or the rounded back of a teaspoon to gently press an indentation in the center of the cookie dough balls. Repeat with all of the dough balls. Transfer to freezer; chill for 30 minutes.
Once dough is done chilling, preheat oven to 375 degrees F.
Place preserves/jam in a small microwave-safe bowl. Heat for about 5-10 seconds or until jam is not hot but is no longer firm and is easy to stir. Spoon p;reserves/jam into each thumbprint, filling each indentation to the brim.
Once oven is preheated, place cookies at least 2 inches apart on a parchment paper-lined cookie sheet. Bake for 11 minutes or until edges are just beginning to turn golden brown.
Allow cookies to cool completely on the baking sheet before serving.
24 cookies.