Put berries, water and sugar in a saucepan and gently bring to the boil. Stir in the cornflour and water mix and cook until thickened. Pour into a container and cover. Refrigerate.
Put butter and honey into a saucepan and heat until melted. Stir in the remaining ingredients. Spread out onto baking paper and bake at 160°C until golden and crisp. Store in an airtight container.
Layer the yogurt and berry mixture by spooning into the glasses alternately. Top with muesli clusters and fresh berries.