Who doesn't love a crumble? This delicious dessert has a crumble topping with a twist.
Preheat the oven to 180C/gas 4 and have ready an oven dish roughly 25cm x 20cm.
To make the filling put the apple, butter and sugar in a pan. Cook over a medium heat for about 10 minutes, stirring from time to time, until the sugar has dissolved and the fruit is just beginning to collapse. Taste and add more sugar if required. Stir in the blackberries and transfer the mixture to the oven dish and set aside.
To make the crumble topping, combine the flour, oats, dulce and sugar in a bowl. Add the butter and rub in lightly with your fingertips until the mix resembles coarse crumbs.
Using a pestle and mortar or a small processor, crush the seeds so they break down a little. Do not reduce them to a fine powder. Stir the crushed seeds into the crumble mixture.
Spoon the crumble mixture over the filling. Bake for 35-40 minutes until golden brown and bubbling. Leave to settle for about 10 minutes, then serve with custard, cream or ice cream.