Blackberry And Apple Crumble Cake

• 680 cooking apples
• 450 blackberries
• 10 arrowroot mixed with
• 10 mins until the fruit
• 1 lemon
• 1 egg
• 130 gr caster sugar
• 120 gr flour (plain)
• 60 ml water (cold)
• 40 gr butter (unsalted)