Add flour, salt and half the sugar to the bowl of a stand mixer and mix
In a separate bowl, add yeast, luke-warm water and remaining sugar and let sit for 15 minutes, until foamy
Add yeast mix to flour in a stand mixer bowl and mix until a shaggy dough forms
With the mixer running, add a knob of butter at a time until fully incorporated
Mix for ten minutes or until a smooth shiny dough is created.
Place dough in an oiled bowl and cover. Leave to proof for 1-11/2hours or until doubled in size
Punch down dough and roll out. Stamp out rounds with a cookie cutter.
Place dough rings and holes on parchment paper squares. Cover and proof until risen and puffy.
Lift parchment paper square with donut ring into hot oil and remove paper with tongs.
Fry for 2 minutes on each side or until golden.
Dip each ring into blackberry glaze and sprinkle with pearl sugar to decorate