This combination of lavender honey ice cream and cake that is covered with meringue and briefly baked is a classic dessert.
Preheat the oven to 325 ºF (160 ºC). Line the bottom of a 12-x-17-inch baking pan (with a lip) with parchment paper.
Whip the eggs and sugar on high speed until they are almost white in colour, more than triple in volume and hold a ribbon when the beaters are lifted, about 5 minutes.
Sift the flour and salt and, still on medium speed, add them to the eggs and mix until combined. Spoon about a cup of the batter into a bowl, and stir in the melted butter and vanilla. Add this all back to the full batter and fold in on low speed or by hand until blended. Pour the batter into the prepared pan, spread to ensure it is as level as possible and bake for about 25 minutes, until the centre of the cake springs back when gently pressed. Cool the cake completely in the pan.
For the ice cream, heat the 10% cream in a small saucepan over medium heat, along with the lavender blossoms and the scraped seeds and the vanilla pod until it just begins to come to a simmer. Remove the vanilla pod. Whisk the egg yolks and sugar in a small bowl. Slowly pour the hot cream into the egg mixture while whisking constantly, and add this back to the pot. Switch to a wooden spoon and stir the cream (still over medium heat) until it coats the back of the spoon, about 4 minutes. Pour the crème anglaise through a strainer and cover the surface of it directly with plastic wrap. Cool to room temperature and then chill completely. Prepare to freeze the ice cream when you are ready to assemble the baked Alaska.
When ready to assemble, whisk the whipping cream and honey into the chilled custard and pour into an ice cream maker following manufacturer’s instructions. This can take around 20 minutes, so while churning, prepare the cake.
Use a bowl that holds 10 cups (2 ½ L) by volume as your mold. Line the bowl with plastic wrap so that it hangs over the sides. Loosen the cake from sides of the pan, turn out onto a cutting board and peel away the parchment paper. Cut a circle of cake to fit in the bottom of the bowl, and cut strips of cake that fit in the bowl to fully line the bowl so that there are no visible gaps (but it doesn’t have to look perfect, since the entire cake will be covered with meringue). Once the ice cream is frozen but still soft, spoon it into the bowl, spreading to level it. Top the ice cream completely with remaining cake, wrap and freeze until firm, about 4 hours.
The meringue should be prepared immediately before serving the Baked Alaska. Preheat the oven to 450 ºF (230 ºC).
Whisk the egg whites and the sugar in a metal bowl. Place the bowl over a saucepot filled with an inch (2.5 cm) of gently simmering water and whisk until the egg whites are warm to the touch. Use electric beaters or transfer the whites to a stand mixer fitted with a whip attachment and whip until the meringue is glossy and holds a stiff peak when the beaters are lifted, about 4 minutes.
Pull the ice cream cake from the freezer and turn it out onto an inverted baking tray lined with parchment paper, removing the plastic wrap. Spread the meringue over the entire surface of the cake, swirling the meringue to create a pretty pattern. Bake the cake for 3-4 minutes, until it just begins to brown. Immediately transfer the cake to a serving plate, bring to the table and slice to serve with fresh raspberry coulis.