Directions

1. Preheat the oven to 180C or 160C for fan assisted. Grease and line the base of a 20cm (8inch) round springform tin with greaseproof paper. Set aside.Blitz 85g of gluten free oats in a small food processor until it resembles flour. Alternatively rub the oats into a dust using your fingers.

2. Place 15g of oat flour, into a bowl and set the rest aside to use later. Add the gluten free oats and light soft brown sugar. Melt the butter in a small saucepan and it pour over the sugar and oat mixture. Use your fingers to rub the ingredients together to form small clumps of streusel topping. Set aside to use later. Peel and core the apple and slice into 1cm pieces, then set aside.

3. Place all the cake ingredients, including the 70g reserved oat flour into a bowl and whisk together using an electric mixture until soft and creamy. Spread the mixture into the base of the prepared tin.

4. Arrange the diced apple and blackberries evenly over the top, pressing them gently into the surface of the cake. Scatter over the oaty streusel topping.

5. Bake for 35-40 minutes until risen and lightly golden brown. Allow to cool completely in the tin before removing and serving. Store any leftovers in an airtight container.