Line a baking tray with greaseproof paper.
Blitz the bread into a food processor to make fine breadcrumbs.
Spread the crumbs out on a baking sheet. Scatter over the sugars.
Blitz the hazelnuts coarsely in a food processor or chop by hand.
Mix everything thoroughly, then spread out in a shallow layer over the baking tray.
Place under a hot grill and leave until everything turns golden. Take care not to burn the sugar.
Leave to cool then break up into small pieces.
Add the sugared crumbs to the cream and yoghurt, pour into bowl and mix well then put into a freezer container and mix it over the course of a few hours once an hour until frozen.
Sprinkle with almonds if using, when serving.