For the Base
Preheat the oven to 375 F and line a baking tray with parchment paper.
Cut the puff pastry into a 9-inch circle (or use the shell from a 9-inch removable tart pan to cut a circle with a pretty fluted edge) and place this on the baking tray. Dock the pastry with a fork and bake for about 20 to 25 minutes until an even golden brown. Cool.
For the Pastry Cream
Heat the milk with the scraped seeds of the vanilla bean or the vanilla bean paste until just below a simmer.
In a separate bowl, whisk the egg yolks, sugar and cornstarch. Ready a bowl with the butter, placing a strainer on top of it.
Gradually whisk the hot milk into egg mixture and then return it all to the pot. Whisk this constantly (switching to a spatula now and again, to get into the corners) over medium heat until thickened and glossy, about 2 minutes. Pour this immediately through the strainer, whisking it through if needed, and stir in the butter. Place a piece of plastic wrap directly over the surface of the custard, cool to room temperature and then chill completely until ready to use.
For the Choux Paste
Bring the milk, water, butter, sugar and salt up to a full simmer over medium high heat. Reduce the heat to low and stir in the flour with a wooden spoon, stirring vigorously until the dough “cleans” the sides of the pot (no longer sticks). Scrape this mixture into a large bowl and use electric beaters or a stand mixer fitted with the paddle attachment and beat on medium speed for a minute or 2 to cool it a little.
Break two eggs into a small dish and whisk them just to blend a little. Add these to the flour mixture while still on medium speed and mix until blended. Add the remaining 3 eggs one at a time and mixing well after each addition.
Work with this recipe while the batter is still warm.
For the Profiteroles
Makes 2 recipes of choux paste.
For the profiteroles, preheat the oven to 400 F and line two baking trays with parchment paper.
Fill a piping bag fitted with a large plain tip with the choux paste. Pipe profiteroles, each about 1 ½ -inches across. Wet your finger in cool water and tap any points on the batter. You will need 16 to 18 profiteroles for the torte.
Bake the profiteroles for 10 minutes, then reduce the heat to 190°C and continue to bake for about 15 more minutes, until they are a rich golden brown colour and are very light. Allow the pastries to cool completely before filling.
To fill, stir the pastry cream to soften and fill a piping bag with a medium plain tip (or an éclair or doughnut tip, if you have one). Use a skewer to first poke a small hole in the side of each profiterole. Insert the piping bag and fill each with cream until you feel resistance. Save any remaining pastry cream for the torte. Chill until ready to dip in caramelised sugar.
For the Assembly
Bring the water, sugar and corn syrup up to a boil in a small pot over high heat and continue to boil, uncovered and without stirring, and occasionally brushing the sides of the pot with water, until it is a light amber colour. Ready a bowl of ice water and carefully set the bottom of the pot into the ice water to halt the sugar from cooking further.
Using tongs, carefully dip the tops of the profiteroles halfway into the caramelised sugar and place them, caramel side down, on a lightly greased parchment-lined baking tray to set. If the caramel in the pot begins to set before you have finished, you can reheat the caramel on low heat.
To assemble, whip the cream and skim milk powder until it holds a soft peak and stir in the sugar and vanilla. Divide the cream in half, stir the raspberry puree into one half and then fill 2 piping bags fitted with a plain or star tip each with a cream.
Place the baked puff pastry disc onto the serving plate. Spread the remaining pastry cream on the bottom, leaving a half inch space around the outside edge. Arrange the dipped profiteroles on top of the puff pastry, creating a ring around the outside and so that the flat, caramel-dipped tops are facing up. Sprinkle the fresh raspberries over the pastry cream. Pipe alternating straight lines, circles or other patterns with the two colours of whipped cream and chill until ready to serve.
The St. Honoré is best served the day it is assembled, but the separate parts, pastry base, profiteroles and pastry cream, can be prepared a day ahead.