Place the potatoes into a large pot and cover with cold water. Cook the pot over high heat and bring the water to a boil. Reduce the heat to medium low and cook the potatoes on a simmer until fork tender, about 45 minutes.

In the meanwhile, make the bread crumb topping: Add the butter into a wide skillet over medium heat. Once the butter is melted, add the breadcrumbs and toast them until golden brown, stirring often. Once the breadcrumbs are golden brown transfer them onto a heatproof plate and set aside.

Make the poppy seed topping: Place the ground poppy seeds, powdered sugar, lemon zest,  toasted breadcrumbs and powdered sugar in a bowl. Mix well until the mixture is combined. Set side. 

Fill up a large pot halfway up with water. Add 1 tablespoon of salt and bring the water to a boil over medium high heat and place a lid to cover. Keep this water boiling on the stove.

Once the potatoes are fork tender, drain them and let them cool enough so that you can easily handle them. Peel the potatoes and grate them into a large bowl or put the potatoes through a potato ricer. Place the grated or riced potatoes into a mixing bowl and add the eggs, salt, vanilla, and flour. Mix the ingredients with a wooden spoon or by hand until a dough is formed. Turn the dough onto a floured surface and use your hands to form a ball. Divide the dough into two piece and roll each piece into a long log that is about 1 inch thick. Use a sharp knife to cut each log crosswise into inch long pieces, these will be cooked into nudli. Drop half of the pieces of dough into the pot of boiling water. While the nudli cook they will rise to the surface. Continue cooking for 1 more minute and the nudli should be ready. Use a slotted spoon to scoop out the cooked nudli and place them into the bowl with the poppy seed and breadcrumbs mixture. Toss to evenly coat the nudli. Repeat cooking the remaining nudli and coating them in the poppy seed mixture.

Serve hot with a light dusting of powdered sugar on top and prune jam on the side.