Preheat oven to 400.In a bowl, combine all the ingredients, except the jam, until a dough forms.Roll the dough into balls and place onto a lined baking sheet.Use your thumb to make an indent into each cookie.Place the cookies in the freezer for 10 minutes to solidify the shape for baking.Bake for 8-10 minutes. You can tell they are done when the edges are slightly browned.Once the cookies are done, place a small amount of jam into each thumbprint.Place the cookies in the fridge to chill.Serve the cookies once they have firmed up a bit.These cookies are best served the same day they are baked.