Raspberry Thumbprint Cookies

Preheat the oven to 350ºF.

Cream the butter and sugar together until light and fluffy, about 3 minutes. Add the egg, then vanilla and salt, mixing well. With the mixer on low speed, slowly add the flour and mix until it just comes together.

Roll the dough into small balls, and place on a lined baking sheet a few inches apart (cookies will spread). If the dough is hard to work with, refrigerate it for 30 minutes.

Using the back of a utensil, or your thumb, create a hollow in each cookie for the jam. Fill with jam.

Bake for 18 to 20 minutes; the edges will be set, but the cookies should not be browned at all, and will not look done. Let the cookies cool for 1 minute on the sheet before moving them to a cooling rack.

If desired, fill with more jam.