Preheat the oven to 180 degrees Celsius (350 degrees Fahrenheit).

Put the cornstarch, salt, flour, sugar, and cocoa powder into a bowl and stir until combined. Add the melted butter and continue to mix it until it’s a crumbly dough.

Sprinkle chunks of cookie dough onto a baking sheet lined with baking paper, such as Gefen Parchment Paper, and bake for 20 minutes. They will be quite soft when you first remove them from the oven but will crisp up as they cool. Once cold, tip half into an airtight container for later.

Break the milk chocolate into pieces and place in a bowl. Microwave on high for one minute, stir, then microwave 30 seconds, stir again, and repeat in 30-second bursts until it is completely melted. Pour half the crumbs into the bowl of melted chocolate and mix until they are coated. Spread out on a lined baking sheet and place in the refrigerator.

Preheat the oven to 180 degrees Celsius (350 degrees Fahrenheit).

Place chocolate and margarine into a bowl and melt in the microwave on high for one minute. Stir the mixture, then microwave for another 30 seconds and stir again. Repeat in 30-second bursts, stirring in between each time, until melted. Mix in the sugar. Then add the eggs and whisk well. Sift the flour, cocoa powder, and baking powder together and mix into the cake mixture until just combined.

Pour into two 10- x 15-inch (25.5- x 38-centimeter) lined cake pans. Bake in the oven  for 15–20 minutes or until a knife inserted into the center comes out clean. If your cake is looking done on top but is not yet cooked in the middle, place an empty baking sheet on the oven shelf just above it to protect the top from burning.

Cool on a wire rack.

Combine the water, sugar, and glucose syrup in a pan. Place over high heat and stir until the sugar is dissolved. Using a wet pastry brush, wash any sugar off the sides of the pan. Leave it to boil unstirred for four to six minutes or until it has a golden caramel color. Add the milk and cream, being careful of the burst of steam. At first the caramel will set because the liquid is cool, but continue stirring until the caramel melts completely.

Let the mixture boil unstirred until it reaches 107 degrees Celsius (224 degrees Fahrenheit) on a candy thermometer—this will take about two to three minutes. Strain through a sieve into a heatproof bowl. Add in the salt, then stir through and leave the mixture to cool.

Quickly mix the gelatin with three tablespoons (45 milliliters/1.5 fluid ounces) of the milk and set aside.

Place the milk and glucose syrup in a large bowl and microwave on high until it bubbles. In a separate bowl, whisk the egg yolks with a little of the hot milk mixture to temper them. Add the rest of the hot milk mixture, whisking as you do so. Microwave for five seconds more. Add the softened powdered gelatin into the milk mixture and stir until melted.

Pour this mixture over the chocolate and leave it for a couple of minutes until it melts. Stir well with a whisk until your mixture is smooth. Leave to cool to room temperature.

Fold in the whipped cream and use immediately or the mousse will set.

Shortly before assembly, prepare the Italian meringue. Whisk the egg whites and cream of tartar until they form soft peaks.

Put the sugar and water in a saucepan and bring to a boil. Wash down the sides of the pan with a wet pastry brush, add a candy thermometer to the side of the pan, and leave unstirred until it reaches 114 degrees Celsius (238 degrees Fahrenheit).

Immediately remove the sugar solution from the heat and, with the beaters running, pour in a thin stream into the egg whites. Continue to whisk on high speed until the outside of the bowl no longer feels hot. This usually takes about five minutes. You can speed up the cooling process by putting a bowl of iced water underneath the mixing bowl. It will be thick, smooth, and glossy when it is cool.

Level the cakes and cut two eight inch (20 centimeter) circles from each cake. Reserve the cake offcuts as you will need them later.

Place a 20-centimeter (eight-inch) cake ring onto a cake board and line with acetate. Beware: your mousse will seep out the bottom if your cake ring isn’t totally flat on the board. To keep this from happening, put about 1/4 cup of mousse in the bottom, ensuring it is around all the edges, and place in the freezer for a few minutes so that it firms up quickly and seals any little gaps.

Place a layer of cake into the bottom of the cake ring, then sprinkle two tablespoons of milk over the cake layer. Add a handful of chocolate-coated cookie chunks. Drizzle on some divine salted caramel. Cover with two-and-a-half-cups or 625 milliliters (21 fluid ounces) of chocolate mousse.

Continue to layer it up in this manner all the way to the top. Refrigerate for at least three hours, preferably overnight.

Chop the chocolate bars into triangular chunks. If they contain caramel, you may need to put them in the freezer to make them easier to handle.

Remove the cake ring and peel off the acetate from the outside of the cake. Add caramel around the top edge, allowing some to drip down the sides of the cake.

On top of the cake, pile some cake offcuts across the center, then add crunchy cookie crumble on both sides.

Generously spoon Italian meringue across the middle so that it covers the cake offcuts. Toast the meringue using a blowtorch, then top with strawberries, edible flowers, and the chopped chocolate bars.