Preheat oven to 350 degrees F. Coat 2 baking sheets with cooking spray.< br>
In a large bowl, cream sugar, butter, and peanut butter with an electric mixer on low speed. Beat in eggs and vanilla. Add flour, baking soda, and salt; mix well..< br>
Shape dough into 1-inch balls and place on prepared baking sheets. Press thumb into center of each cookie to make an indentation. Fill each indentation with a teaspoon of strawberry preserves. Sprinkle with peanuts, if desired.
Bake 12 to 15 minutes, or until light golden. Cool 10 minutes then remove to cooling rack to cool completely.