Toast the almond leaves in a naked pan. Set aside.
Whisk together the sugar, cardamom, cinnamon, nutmeg, and salt. Set aside.
Slice the plums into thin wedges. Discard the pits.
Dice the marzipan
Heat the butter in a large skillet.
Add the plum slices and toss to coat.
Mix in the raisins.
Sprinkle the sugar/cardamom mixture over the top over the top and mix to coat.
Cook for 5 minutes, stirring occasionally.
Remove from heat. Fold in the marzipan pieces and 1/2 cup of the toasted almonds. Let cool.
Preheat the oven to 350F. Line a baking sheet with parchment paper.
Roll out the puff pastry sheet. Not too much. You don’t want it too thin.
Transfer it to the backing sheet & spread the breadcrumbs over the top.
Spoon the plum mixture down one half of the puff pastry sheet leaving a 3/4 inch edge.
Fold the other half of the puff pastry sheet over and seal the edge with your fingers.
At this point I lift up the parchment paper to gently roll the strudel so the seam is on the bottom.
Beat the egg and brush it over the strudel.
Bake for 30 minutes until the top is crispy.
When the strudel is cool enough to handle, transfer it to a baking rack & place it over the parchment-lined baking sheet.
Let cool completely.
Whisk together the powdered sugar and liquid.
Whisk in the ground cardamom.
Pour the glaze over the strudel.
Sprinkle with the remaining 1/4 cup of toasted almond leaves.
When the glaze has hardened, cut and serve.