1. Add the flour, xylitol (or sugar), cinnamon, and salt for the dough to a large bowl and mix until well combined. Add the cold butter in small cubes and cut with a pastry blender* into pea-sized pieces. Add the egg and mix in. Knead until the dough starts coming together. Form into a ball, flatten and wrap in plastic wrap. Place in the fridge for about 1 hour (or overnight).

2. Lightly grease a 9 inches (23cm) pie dish and set it aside. Roll out half of the dough slightly larger than the pie dish, transfer to the dish, and press to the bottom and sides. Cut off overlapping dough, but keep a border of about 0.6 inches (1,5cm). Place in the fridge until needed.

3. Roll out the remaining dough and cut into 0.8 inches (2cm) wide strips for the lattice topping. Place in the fridge until needed. Toast the sliced almonds in a dry pan until fragrant and slightly browned. Set aside and let cool down a bit.

4. For the filling wash and dry the damson plums. Remove the stones and quarter the plums. Place in a large bowl. Mix the xylitol (or sugar) with cornstarch and cinnamon. Add together with the vanilla extract to the bowl and mix to combine. Add the toasted almonds and the butter in very small cubes and mix in. Transfer to the pie dish. Try to press the filling down a bit to compact it. Place the dough strips on top of the filling and create a lattice. Press the edges together and create a nice crimped edge. Place the pie in the fridge while the oven is heating up.

5. Preheat the oven to 425°F (220°C) including a baking sheet sitting in the lower third of the oven. Mix the egg yolk with some water and brush the dough lattice and the edge of the pie. Sprinkle everything with some coarse sugar and place the pie on the hot baking sheet. Bake for about 20 minutes, then lower the temperature to 350°F (180°C) and continue baking for 45-50 minutes. The pie should have a nice golden brown color and the filling should bubble nicely. If the pie is getting too dark, cover towards the end of the baking time. Take out of the oven and let cool down for at least 4 hours (or overnight) before slicing. Serve with some whipped cream or ice cream.