How to Make It
Prepare the House Patterns: Draw 2 (6¾- x 6¼-inch) rectangles on parchment paper for roof, leaving at least 5 inches between pattern pieces. Draw 2 (5¼- x 2¾-inch) rectangles on parchment paper for sides, leaving at least 5 inches between pattern pieces. Draw 2 (7¾- x 6½-inch) pentagons on parchment paper for ends, leaving at least 5 inches between pattern pieces and starting peak for roof 2¾ inches from bottom. Get the template.
Prepare the Royal Icing: Place powdered sugar, meringue powder, and 3 tablespoons of the water in a medium bowl, and stir until smooth. Stir in up to 1 tablespoon water, 1 teaspoon at a time, until desired consistency is reached. (Icing should be firm but easy to squeeze through a small hole in piping bag.) Place ½ cup icing in a bowl; stir in desired amount of red food coloring. Place ½ cup icing in a separate bowl; stir in desired amount of green food coloring. Cover each bowl with a damp paper towel; cover tightly with plastic wrap. Keep at room temperature until ready to use. Transfer remaining icing to a disposable piping bag; twist the large opening, and secure with a rubber band. Snip a small hole in the pointed end of the bag. Keep opening covered with a damp paper towel when not using to keep the icing from getting hard.
Prepare the House: For the roof, arrange graham cracker sheets on each roof pattern; carefully trim edges to fit. Pipe icing along edges of crackers, and press together to secure. Let dry completely, about 1 hour. Arrange nonpareil disks over crackers in shingle style, securing with icing. (You may need to cut 1 row of nonpareil disks in half to cover graham crackers.) Let dry completely, about 1 hour.
Trim edges and ends off regular-size Kit Kat pieces. Trim edges and ends off 25 miniature white chocolate Kit Kats and 25 miniature milk chocolate Kit Kats. (Trimming the edges off will make a more secure even fit when they are “glued” together.) Melt chocolate candy coating according to package directions.
For the sides and back of house, arrange regular-size Kit Kats, alternating white chocolate and milk chocolate horizontally, over pattern pieces, cutting as necessary to fit the pattern. Spread a layer of melted chocolate candy coating on the edges of Kit Kats, and press together to adhere. Let dry completely, about 30 minutes. Carefully trim edges to fit pattern.
For the front of house, secure together 5 regular-size milk chocolate pieces for the door. Place door in center on pattern. Arrange miniature Kit Kats, alternating white chocolate and milk chocolate, around door, securing with melted chocolate candy coating. Let dry completely, about 30 minutes.
To assemble house, secure ends to sides with melted chocolate candy coating. (Use soup cans to help hold in place while icing dries.) Let dry completely, about 1 hour. Secure roof by liberally apply icing to peaked portions of ends; press roof pieces in place. (Prop up roof pieces with cans and/or kitchen towels to hold in place.) Fill in any gaps in roof line with icing. Let dry completely, about 1 hour.
Scoop green icing into a piping bag fitted with star tip. Pipe wreath above door on front of house. Scoop red icing into a disposable piping bag; snip a small hole in end of bag. Pipe dots of red onto wreath as desired. Let dry completely, about 1 hour.