Jersey Apple and Blackberry Crumble Slice

Preheat oven to 180°C (350°F/ Gas Mark 4). Grease and line a 9x13 inch baking pan with parchment paper, leaving an overhang for easy removal.

For the base, in a large bowl, combine the mashed Jersey Royal potatoes, flour, and brown sugar. Add the cubed Jersey butter and rub it into the dry ingredients with your fingertips until the mixture resembles breadcrumbs.

Press half of the crumble mixture evenly into the prepared baking pan. This will form the base of your slice.

In a separate bowl, prepare the apple and blackberry filling. Combine the diced Jersey apples, blackberries, granulated sugar, lemon juice, cornstarch, and cinnamon. Mix well.

Spread the apple and blackberry filling evenly over the crumble base.

For the crumble topping, in the bowl with the remaining crumble mixture, add the rolled oats and mix to combine.

Sprinkle the crumble topping evenly over the fruit filling.

If desired, brush the top with a little Jersey milk and sprinkle with a bit of granulated sugar for extra shine and sweetness.

Bake in the preheated oven for 35-40 minutes, or until the crumble topping is golden brown and the fruit filling is bubbling.

Remove from the oven and let cool completely in the pan before lifting out using the parchment paper overhang. Cut into slices and serve.