Prepare the chocolate pie crust first. Place the cold butter, flour, salt and cocoa powder into a food processor. Pulse for about 1 minute, until the mixture resembles fine crumbs. This step can also be done in a large mixing bowl using a pastry cutter or two large forks. Add the water and pulse again for about 1 minute, until a dough ball forms; add 1 tbsp water more, if needed. Wrap the dough in plastic wrap and place into the refrigerator to chill for 1 hour.

Meanwhile, prepare the filling. Into a medium sized sauce pot, add the sugar and water and DO NOT stir. Cook the sugar syrup over medium heat, bringing it to a simmer. Continue boiling the syrup for 6 to 10 minutes, until it darkens into a golden amber color. Remove the pot from heat and add the butter and heavy cream and stir until the butter is melted.

Next, add the chocolate, vanilla and salt. Let the chocolate stand for 1 minute, then whisk the sauce until it's smooth. Cover the sauce and let is stand at room temperature, cooling.

Prepare the raspberry sauce next. Place the raspberries and sugar into a sauce pan and bring to a simmer over medium heat; add 2 tablespoons (30 ml) of water, if needed. Simmer the raspberries for 5 to 6 minutes, until they're softened. Pour the resulting sauce into a fine-mesh strainer arranged over a large bowl. Using the back of a spoon, press the raspberries until just the seeds remain. Discard the seeds and place the raspberry sauce into a small bowl or cup.

Preheat the oven to 350F/177C. Once the crust has chilled, roll it out on a lightly floured work surface. This recipe will work with an 8, 9 or 10-inch tart pan. Roll the dough out 1-inch bigger than the pan, then gently transfer it into the pan, press it lightly into the pan and discard any overhanging dough. Pierce the bottom of the dough with a fork to prevent air pockets.

Line the crust with a round of parchment paper and add pie weights or beans, to prevent the crust from shrinking. Bake the crust in the preheated oven for 15 minutes with the pie weights, then remove the weights and paper and continue baking for another 10 minutes. The crust needs to be well done and crispy.

Once the tart crust has cooled, gently remove it from the pan and transfer onto a cake stand or tray. Add the prepared chocolate caramel sauce and spread it evenly to the edges. Next, add a light layer of the raspberry sauce, reserving about 1/3 for serving. Add the fresh raspberries on top, pressing them gently into the sauce.

Keep the tart refrigerated if not serving right away. Remove from the refrigerator about 30 minutes prior to enjoying. Serve with any remaining raspberry sauce.