Strawberry Shortbread Thumbprints

I made these cookies this morning for my husband to take to his cricket game.  He didn't end up going so we get to eat them, yay!  I adapted the recipe slightly from one on Allrecipes, you can find the original here: http://allrecipes.com/Recipe/Raspberry-and-Almond-Shortbread-Thumbprints/Detail.aspx

Strawberry Shortbread Thumbprints 
1 cup butter, softened
2/3 cup white sugar
1/2 teaspoon vanilla extract
2 cups all-purpose flour
1/2 cup strawberry jam

Preheat oven to 350 degrees F (175 degrees C).

In a medium bowl, cream together butter and white sugar until smooth. Mix in 1/2 teaspoon vanilla extract. Mix in flour until dough comes together. Roll dough into 1 1/2 inch balls, then flatten into rounds and place on ungreased cookie sheets. Make a depression in the center of each cookie, using your thumb and fill the hole with jam.

Bake for 11 to 15 minutes in preheated oven, or until lightly browned. Let cool 1 minute on the cookie sheet.