Classic, easy jam thumbprint cookies recipe from scratch, homemade with simple ingredients. Soft and tender sugar cookies are indented and filled with jam!
Cream together butter and sugar until light and fluffy.
Add egg yolk (NO egg whites!), vanilla extract and mix until smooth.
Add flour and mix until just combined. The dough will become dry and crumbly. Don't worry!
Use your hands to combine the crumbles together into a ball of cookie dough. Add a splash of milk or water to help bring the dough together, if necessary. Typically, the warmth of your hands should be enough to bring the crumbles together.
Scoop out small portions of the dough and make little balls. Make sure they are smooth and there are no cracks to prevent cookies from cracking on the edges during baking.
Roll cookie balls in a bowl of granulated sugar and place them on a cookie tray, lined with parchment paper.
Gently, press your thumb in the center of each cookie ball to create an indentation.
Chill trays with these cookie balls in the freezer for at least 30 minutes. You cannot omit this step or else the cookies will spread during baking!
Fill each thumbprint with warm jam or preserves.
Bake at 375 degrees F for 10-12 minutes or until edges are firm and golden brown.