Plum Tart with Cashew Cinnamon Crumble

1. Mix 250g / 8.82oz wholegrain spelt flour and 250g / 8.82oz spelt flour (Type 630) in a bowl.
2. Warm 250ml / 8.45fl oz unsweetened oat drink.
3. Crumble 12g / 0.42oz fresh yeast into the oat drink, add 3 tbsp / 42g date syrup, and mix.
4. Make a well in the flour, pour in the yeast mixture, mix with some flour to form a pre-dough, and let rise for 15 minutes.
5. Add 1 pinch / 0.36g salt, 1 egg yolk, 50g / 1.76oz soft butter, and 80g / 2.82oz unsweetened apple puree, knead to a smooth dough.
6. Let rise covered in a warm place for another hour.
7. Grease a baking tray or line with parchment paper.
8. Knead the dough, roll out to fit the tray, place on the tray, and let rise covered for another 15 minutes.
9. Preheat the oven to 200°C (392°F).
10. Wash, halve, and pit 1200g / 42.33oz plums.
11. Grind 100g / 3.53oz oats and 50g / 1.76oz cashew nuts in a food processor.
12. Mix with 40g / 1.41oz date syrup, 2 tsp / 5.2g cinnamon powder, and 60g / 2.12oz cold butter to make crumbles.
13. Place plums cut side up on the dough.
14. Sprinkle crumbles over the plums.
15. Bake in the oven on the middle rack for about 35 minutes until golden brown.
16. Remove and let cool on the tray.