Put the raspberries, sugar, salt, and lemon juice in a saucepan over medium-low heat. Stir until the sugar dissolves, then cook for 10 to 15 minutes, or until the mixture looks thick and glossy.

Let it cool for about 20 minutes, then chill it until cold. This can be done up to 3 days ahead.

Whisk the egg yolks, sugar, salt, vanilla, and cornstarch until smooth.

Heat the milk until it just begins to steam, then whisk about half of it into the yolk mixture.

Pour everything back into the pan and cook over medium-low heat, whisking all the while, until it thickens and just starts to boil.

Remove it from the heat, whisk in the butter, and press plastic wrap directly onto the surface. Let it cool for about 15 minutes, then refrigerate until fully cold.

Heat the oven to 325°F and prepare a 9- to 9.5-inch round pan by lining and greasing it.

Melt the butter with the milk, then let the mixture cool for 10 to 15 minutes until it is just warm.

Whip the eggs and sugar until pale, thick, and about doubled in volume.

Beat in the vanilla and almond extracts.

Whisk together the flour, baking powder, and salt.

Gently fold the dry mixture and the milk-butter mixture into the whipped eggs in alternating additions to keep the batter airy.

Pour the batter into the pan and bake for 30 to 35 minutes, until golden and a tester comes out clean. Cool it fully on a rack.

At the same time, make the marzipan by mixing the almond flour, powdered sugar, almond extract, and 4 tablespoons water into a dough.

If it feels crumbly, add more water, 1 tablespoon at a time, until it feels like soft clay. Set aside a small 2-inch ball for the rose. Knead green coloring into the larger portion and a tiny bit of pink or red into the smaller ball.

Roll the green marzipan between sheets of parchment until it is about 1/4 inch thick and large enough to cover the cake.

Whip the cream with the vanilla and optional powdered sugar to stiff peaks.

Level the dome off the sponge and cut it into three even layers.

Place the first layer on a serving plate and spread it with jam.

Add the second layer and spread on the pastry cream.

Top with the third layer, then pile the whipped cream on top and shape it into a dome. Smooth a little cream down the sides so the marzipan will stick.

Drape the green marzipan over the cake in one smooth motion. Smooth out air pockets as best you can, then trim away the extra around the bottom.

Add a small green collar at the base and place the marzipan rose on top.

Dust the finished cake with powdered sugar if desired.

Refrigerate and serve within 3 to 4 days for the best texture.