Chocolate Thumbprints

Why I Love This Recipe
I make several batches of these every Christmas and they tend to disappear very quickly! (Recipe courtesy of 'Handmade Christmas' by Martha Stewart)
Ingredients You'll Need
12 tablespoons (1½ sticks) unsalted butter
½ cup confectioners sugar
¼ teaspoon salt
1 teaspoon vanilla extract
1¼ cups all-purpose flour
4 ounces semi-sweet chocolate, chopped
1½ teaspoons corn syrup
Directions
Heat oven to 350 degrees.
In the bowl of an electric mixer, beat together 1 stick butter, salt, sugar, and vanilla on medium-high speed with paddle attachment until smooth, about 2 minutes.
Beat in flour, beginning on low speed and increasing to medium-high.
Roll dough by teaspoonfuls into balls and place 1 inch apart on an ungreased baking sheet.
Bake for 10 minutes, remove from oven, and press thumb into tops of cookies to make indentations. Return to oven and bake until light brown on the edges, 7 to 9 minutes more.
Remove to a wire rack to cool.
Combine the chocolate, 4 tablespoons butter, and corn syrup in a small heatproof bowl.
Set over a pot of simmering water; stir occasionally until melted and smooth.
Allow to cool slightly.
When cookies are cool, fill the thumbprints with the chocolate mixture.
Yield 2 dozen.