Martha Stewart's Holiday Cookies - Strawberry Thumbprints

This is one of Martha's easier recipes and it makes a great holiday cookie if you're putting together goodie baskets. The recipe didn't say if butter should be softened or not however, butter straight out of the fridge does not mix well. I let mine sit out so it was room temperature.

Ingredients:

• 3 cups all-purpose flour
• 1/2 teaspoon salt
• 2 sticks (1 cup) unsalted butter
• 1 cup sugar
• 1 egg
• 2 teaspoons vanilla extract

Preparations:

1. Combine butter, sugar, egg and vanilla. Beat well.
2. Separately, mix flour and salt. 
3. Add flour to butter mixture slowly with electric mixer on low.
4. Roll dough into one inch balls and place on lined cookie sheet. Refrigerate for 30 minutes. 
5. Preheat oven to 350 degrees.
6. Bake dough for seven minutes. Remove from oven and make sure well of cookies is still deep. If not, press with end of wooden spoon or baby spoon.
7. Return to oven and bake for 7 to 9 minutes or until cookies are firm. 
8. Let cool completely. Spoon jam filling into thumbprints.