Method

• 1.
  Prepare cookie base recipe and bake as 12 individual cookies according to packet instructions. Cool completely, break into large chunks and, in 2 batches, whiz in a food processor to fine crumbs. Add the butter and pulse to combine.
• 2.
  Grease a 2L loaf pan and line with plastic wrap, leaving plenty overhanging the sides. Press one-third of the cookie mixture into base of pan. Working quickly, spoon over gelato, then spread over dulce de leche. Scatter with half of the remaining cookie mixture, pressing into an even layer. If gelato is getting too soft, freeze for 20 minutes before working on next layer. Spread vanilla gelato over the top, then top with remaining cookie mixture. Freeze for 4 hours or overnight until firm and set.
• 3.
  To serve, lift from pan and remove the wrap. Slice thickly, and serve immediately. To make the cover topping: Whisk 1 1/2 cups thickened cream, 2 tbs icing sugar and 1 tsp vanilla bean paste to firm peaks. Stir 1/4 cup dulce de leche and 3 tsp water in a bowl until smooth. Top slice with cream, 1/3 cup coconut flakes and dulce de leche.