1. Cream castor sugar and softened butter until pale and fluffy.

2. Add eggs, one at a time and mix until well combined.

3. Add vanilla extract, mix until combined.

4. Sift in self raising flour and mix until just combined.

5. Pour cake batter in to lined slow cooker. Mix will be thick and sticky, spread out evenly.

6. Sprinkle the frozen raspberries and add an even layer of the tinned or stewed apples.

In a bowl prepare your crumble mixture:

- Use fingers to rub the butter, plain flour, sugar, oats together to resemble crumbs.

7. Sprinkle the crumb mixture over the cake.

Cook in the slow cooker On high for approximately 2 hrs/ Low for 3 hrs or (in my case, low for 2.5 hrs and then switch to high for 30-45 minutes)

Cook with lid on and a tea towel under the lid to absorb any moisture.

You can add another frozen fruit - doesn't have to be Raspberries.