Line 2 baking sheets with nonstick baking paper. Roll out the cookie dough on a lightly floured surface. Cut out 10 x 8 cm (4 x 3¼ inches) rectangles and transfer to the baking sheets.
Cut out 4 squares from each rectangle to resemble window panes. Gather the trimmings and reroll the dough to make more window shapes. Place the windows on the baking sheets and put a boiled sweet in each cut out square.
Bake in a preheated oven at 180°C (350°F), Gas Mark 4 for 12 minutes or until the cookies begin to colour and the sweets have melted to fill the frames. If necessary ease the sweets into the corners with a toothpick. Leave to cool on the baking sheets. Place the icing in a piping bag fitted with a fine plain nozzle. Pipe a little icing onto the back of each flake bar and secure one flake along the base of each cookie. Make sure the chocolate sits straight along the bottom so it supports the cookie.
Add flower petals and trailing leaves around the windows, using the remaining icing in the bag. Before it sets, press small candies into the frames in the centres of the windows.
Leave to cool before carefully peeling away the paper.