1. Heat oven to 350 degrees F. Grease 12-cup 3-inch muffin or muffin-top tin; or for free-form cookies, line baking sheet with aluminum foil; grease.
2. Combine sugar, butter, corn syrup and milk in saucepan. Over medium heat, cook until mixture registers 235 degrees F (soft ball stage) on candy thermometer.
3. Remove pan from heat. Stir in almonds, flour, cherries, citron, vanilla. Drop by teaspoonfuls into prepared cups or 4 inches apart on foil.
4. Bake in 350 degrees F oven until edges brown, 7 to 8 minutes. (If free-form, shape into circles while warm.) Loosen cookies with small spatula; remove from cups to wire rack to cool. If cookies stick in cups, return to oven for 30 seconds. Repeat with remaining batter.
5. Melt chocolate chips in bowl over hot (not boiling) water. Spread smooth sides of cookies with chocolate; sandwich 2 cookies, chocolate sides together. Chill to set chocolate.