In a bowl, gently mix together 1 tablespoon of sugar, warm milk, and yeast using a spoon. Set aside for about 10 minutes – it should get foamy.

In the mixing bowl of a stand mixer, cream together the butter, remaining sugar, and egg yolks. Add the rest of the ingredients (except for the blueberry jam), as well as the yeast mixture and mix together to create a dough. Switch to a dough hook and knead for 5-7 minutes. Cover with cling film and allow to proof for 1-2 hours or until doubled in volume.

Line a standard loaf pan (8½ x 4½ or 9 x 5 inches) with parchment paper. Move the dough to a lightly floured surface and roll out the dough into a rectangle, about ¼-inch thick. Spread the jam evenly on the dough surface and roll up in a log. Cut the log in half lengthwise, so that you have two long halves and then twist these together like a rope. Place it gently into the loaf pan. Allow to proof for another 1-2 hours or until almost doubled.

Preheat the oven to 360°F. Bake for about 45 minutes. Let cool in the pan. Serve slices topped with fresh blueberries.