Add berries, sugar and lemon to a pot and bring to a boil, stirring occasionally.
Simmer on low/medium for 30 minutes or until it thickens to a jam-like texture.
Allow to cool in the fridge.
Once the dough has doubled in size, divide into 9 equal pieces and roll into balls.
Flatten each dough ball slightly and use your fingers to create an indentation in the centre of each bun.
Place on a parchment lined baking tray, cover and proof for 30-45 minutes.