Preheat oven to 300°

Mix butter until light and fluffy.

Gradually add dry ingredients until well blended. You can use a mixer with a dough hook or a handheld dough cutter.

Dust hands lightly with cornstarch or powdered sugar, roll dough into 1 inch balls, and place on a parchment paper lined baking sheet.

Press each cookie lightly in the center to make an indentation. Fill each with a dollop of your choice of preserves.

Bake at 300° for 20-25 minutes. You want the cookies to be done, but not browned. Just a light, golden tinge on the bottom or edges is fine.