Soak one pint of blackberries in water for a few minutes. Toss sugar with lemon zest, using your fingers.
Drain most of water, add sugar, lemon juice and chill overnight.
In the meantime, set bread on counter, cut into cubes to further dry it out.
Toast bread, butter, add cinnamon sugar. Cut into cubes.
Fry cubes to further crisp (or pop into oven for few minutes).
Toss blackberries with a few grindings of nutmeg and most of the basil, saving some for garnish.
Toss bread and blackberries together. Pour some of the juice onto the bread in each serving.
Garnish with basil.