1/2 cup (1 stick) butter, at room temperature
2/3 cup sugar
1 egg (separate into yolk and white)
2 tablespoons milk
1 teaspoon vanilla
1 cup flour
1/3 cup Dutch-process unsweetened cocoa powder (I used Penzey's)
1/4 teaspoon salt
2/3 cup finely chopped pecans
16 plain caramels, unwrapped
1 tablespoon milk
Beat together butter, sugar, egg yolk, milk and vanilla until well blended. Sift flour, cocoa and salt into batter and mix on low speed till well combined.
Form dough into two logs, each 8 inches long. Whisk egg white till frothy. Paint logs with egg whites and roll in pecans. Wrap in plastic wrap and chill at least 30 minutes.
Preheat oven to 350º. Line two baking sheets with parchment. Cut each log into 16 slices (each about 1/2 inch wide). Arrange on baking sheets, about 1 1/2 inches apart. Use fingers to reshape each cookie back into a circle if needed.
Bake 10-12 minutes. Remove from oven and immediately press center of cookies with finger or end of spoon to make an indentation in each cookie (I used the flat end of a whisk). Allow to cool completely.
Melt caramels and milk in microwave (about 60 seconds or less). Stir till smooth. Spoon a bit of caramel into the center of each cookie. Allow to cool till caramel is set.
Melt chocolate chips and place into a ziplock bag. Snip off a corner and drizzle chocolate over each cookie.