Purée the blackberries with a stick blender, then press through a sieve to extract the seeds.
Melt the white chocolate in a bowl suspended over a pan of hot, but not boiling, water.
Add the purée to the bowl and stir until combined.
Fill six ice-cube holes with the mixture and put any remains in the fridge for future use. Freeze the mixture overnight.
Lava Cakes
Melt the butter in a pan over a gentle heat.
Remove from the heat and add the 100g of roughly chopped white chocolate. Leave for a few minutes then stir until melted and smooth.
Beat in the eggs, one at a time along with the salt and vanilla extract.
Sift in the flour and add the ground almonds. Stir gently to incorporate.
Add 50g of the white chocolate pieces to the batter.
Distribute about 25g of the chopped chocolate between 6 silicone muffin moulds or lined tins.
Cover the chocolate with a spoonful of batter. Place a frozen blackberry ganache on top of each one, then cover with the remaining batter.
Top with a blackberry and the remaining chopped chocolate.
Bake at 160℃ (320℉, Gas 3) for 30 minutes when the cakes should be well risen and golden.
Notes
Serve warm with fresh blackberries if possible.Please note: calories and other nutritional information are per serving. They’re approximate and will depend on exact ingredients used.