Yeast dough:

Cup of Yum
1. Mix the flour, sugar, and salt in a bowl. 350 g all-purpose flour/ 12.5 oz/ 3 cups minus 1 tablespoon + 50 g granulated sugar/ 1.7 oz/ ¼ cup + ¼ teaspoon fine salt
2. Heat the milk gently in a small saucepan (36 degrees Celsius/ 96 degrees Fahrenheit, so body temperature).150 ml milk/ 5 oz/ ⅔ cup
3. Combine: Add butter and yeast to the milk and stir until the butter has melted. Pour the milk mixture and lightly beaten egg into the flour mixture.50 g unsalted butter/ 1.7 oz/ scant ¼ cup + 1 sachet active dry yeast + 1 egg
4. Knead the dough with the hand-held mixer fitted with dough hooks or a stand mixer with a dough hook. Knead as long as possible to combine everything well together. Then, turn the mixture onto the working surface and knead the dough with your hand for a couple of minutes.
5. Let rise: Form a ball, place it back in the bowl, cover it with a clean cloth and let the dough rise in a warm place. The dough will need about an hour until about doubled in size.

Streusel:

1. Mix flour, sugar, and cinnamon in the food processor. Add the very cold butter, cut into cubes, and process shortly until the streusel forms. Refrigerate until needed (Note 3).250 g all-purpose flour/ 9 oz/ 2 cups + 1 tablespoon + 125 g granulated sugar/ 4.5 oz/ ½ cup + 2 tablespoons + ½ teaspoon cinnamon + 150 g unsalted butter/ 5.5 oz/ scant ⅔ cup

Plums:

1. Remove the stones from the plums while the yeast dough is rising. Don't cut the plums all the way through; they should remain attached on one side.1 kg Italian plums/ 2.2. lbs

Assemble:

1. Preheat the oven to 200 degrees Celsius/ 400 degrees Fahrenheit. Line the baking tray with parchment paper.
2. Roll the yeast dough with a rolling pin to match the size of the tray. Carefully place the dough on the tray and stretch and press with your fingers until everything fits.
3. Arrange the stoned plums on top. Sprinkle with the streusel.
4. Bake for 30-35 minutes or until the streusel is golden brown. Let rest for about 20 minutes before slicing it and serve as suggested above.