Chocolate Caramel Treasures
Adapted from Gourmet
Makes about 2 1/2 dozen

I really never grease my sheets when making cookies, but you will need to do so with this recipe.  Or you can use parchment paper.

For Cookies
1 stick unsalted butter, softened
2/3 cup sugar
1 large egg yolk
2 tbsp. whole milk
1 tsp. vanilla
1 cup flour
1/3 cup Dutch-process unsweetened cocoa powder
1/4 tsp. salt
1 large egg white, lightly beaten
1/2 cup finely chopped hazelnuts

For Caramel Filling
10 (1-by 1/2-inch) plain caramels, unwrapped
2 tbsp. heavy cream

For Chocolate Drizzle
3 oz. semisweet or bittersweet chocolate, finely chopped

Make cookies:
Beat together butter, sugar, yolk, milk, and vanilla with an electric mixer until blended well.  Sift in flour, cocoa, and salt and beat on low speed until mixture forms a dough.  Chill, wrapped in plastic wrap until firm, at least 30 minutes and up to 2 days.

Preheat oven to 350°F.  Roll scant tablespoons of dough into balls, then coat with egg white, letting excess drip off, and roll in nuts to coat.  Arrange balls, as coated, 1 1/2 inches apart on greased baking sheets and press your thumb into center of balls to flatten, leaving a depression.  Bake in batches in middle of oven until puffed slightly but centers are still soft, 10 to 12 minutes.  Remove from oven and immediately press centers of cookies again.  (Use the handle end of a wooden spoon.)  Transfer to racks to let cool.

Make filling while cookies are cooling:
Heat caramels and cream in a small saucepan over moderately low heat, stirring occasionally, until melted and mixture is smooth.  Spoon into centers of cookies and cool completely.

Make chocolate drizzle:
Melt chocolate in a double boiler or a metal bowl set over a pan of simmering water, stirring until smooth.  Cool to warm (this will take about 45 minutes) and pour into a sandwich size sealable plastic bag.  Seal bag, press chocolate to one corner and snip off a very small hole.  Drizzle chocolate over cookies and let stand until set, about 30 minutes.