Keep edible flowers in the fridge until you're ready to serve the pie or just before your guests arrive.
Preheat oven to 350 degrees.
Oil your (about 9-inch) baking pie dish with unsalted butter. If you don't have a 9-inch pie pan, it's not the end of the world. Use what you have.
In a food processor, add all the amaretto biscotti or cookies and all the marzipan. Use a spatula to get all of the marzipan out of the can. Then pulse, until you get a nice even batter.
5. Use spatula to scrape all of the crust mixture out of the food processor and into the oiled pie dish. With your fingers, mold the crust mixture so that it covers the bottom of pie dish, as well as the sides.
Now, bake for 10 minutes; then let the crust cool.
Pour 1/2 cup cold water in a saucepan or double boiler, or glass bowl over pot with simmering water. Sprinkle the gelatin over the cold water. While stirring (I like a wooden spoon or spatula) add 1/3 cup sugar, and the 3 egg yolks. Keep stirring to blend. Place over low simmer and stir until the gelatin dissolves and the mixture thickens. Do not boil. You want to be sure, not to cook the eggs. Remove from heat.
Next, stir the Amaretto into the mixture. Then chill until the mixture starts to firm up slightly and not jiggle so much, 30 to 60 minutes in the fridge.
When the Amaretto mixture is ready, in a separate bowl, beat the egg whites until stiff, then add the remaining 1/3 cup sugar and beat this meringue until peaks are firm. Fold the meringue into the thickened Amaretto mixture.
In another bowl, whip the cream, until you get peaks, then fold the whipped cream into the Amaretto mixture.
With a spatula, scrape the Amaretto cream custard mixture into the crust and chill overnight.
Before guests arrive, arrange the edible flowers all over the pie in your own design.