1. Preheat oven to 350°. Pulse first 5 ingredients in a food processor 10 times or until nuts are ground.
2. Beat powdered sugar and butter at high speed with a heavy-duty electric stand mixer 4 minutes or until light and fluffy. Add egg and vanilla, and beat until combined. Add flour mixture, and beat at medium speed 30 seconds.
3. Drop batter by level tablespoonfuls 1 to 2 inches apart on 3 parchment paper-lined baking sheets. Dip finger in cold water, and press into each cookie, forming an indentation. Fill each indentation with 1/2 tsp. apple butter. Dip finger in cold water, and tap down peaks in apple butter.
4. Bake 2 baking sheets at 350° for 14 minutes, placing 1 baking sheet on middle oven rack and 1 sheet on lower oven rack. Rotate pans front to back, and top rack to bottom rack. Bake 4 more minutes or until edges begin to brown. Transfer baking sheets to wire racks, and cool completely (about 10 minutes). Repeat with remaining baking sheet. Drizzle caramel topping over cooled cookies.