Mix flour, baking powder, 1 teaspoon salt and 2 teaspoons sugar. Add milk and oil. Knead to a smooth dough with the dough hooks of the mixer. Let rest at room temperature for about 30 minutes.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Line a baking tray with baking paper. Briefly knead the bread dough again, form it into a round loaf and place it on the baking tray.
Cut the surface with a sharp knife in a diamond shape. Bake in a hot oven for about 45 minutes. Leave to cool.
For the jam: Mix plums (washed, pitted and diced) with ginger (peeled and chopped), cardamom capsules and jam sugar in a large pot and leave to stand for about 1 hour.
Bring the plum mix to the boil over a high heat, stirring constantly, and boil for about 4 minutes until it becomes bubbly. Remove cardamom. Pour jam into prepared twist-off jars, close and turn upside down for about 5 minutes.
Let it cool down. Lasts 3-6 months.