Line a 9x9x2-inch pan with foil, extending over edges; set aside. In a microwave-safe bowl micro-cook butter, uncovered, on 100 percent power (high) for 45 seconds to 2 minutes or until melted. Stir in cocoa powder, brown sugar, and milk. Cook, uncovered, on high for 1-1/2 to 2-1/2 minutes or until mixture comes to a boil, stirring once. Stir again. Cook for 1 minute more. Stir in powdered sugar and vanilla. Spread into pan.

In a glass bowl combine caramels and the water. Cook, uncovered, on 50 percent power (medium) 3-1/2 to 5 minutes or until melted, stirring once. Stir in nuts; spread over fudge.

In a 2-cup glass measure micro-cook chocolate on 50 percent power (medium) for 2 to 3 minutes or until melted, stirring once. Spread atop caramel. Chill until chocolate is firm. Remove from pan; cut into squares. Serve at room temperature. Store in refrigerator. Makes 64 pieces.

Prepare fudge and cut into squares. Cover and chill in refrigerator for up to 3 days. Or, transfer to an airtight freezer container; seal, label, and freeze up to 1 month. Thaw 2 hours at room temperature or overnight in refrigerator before serving.