Instructions

1. Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced. Line and grease an 8-inch round cake pan with baking or parchment paper.
2. To make cinnamon crumble, in a medium-sized mixing bowl, add plain flour, sugar, cornflour, cinnamon and walnuts. Melt butter in the microwave and pour over dry ingredients. Mix together until wet and crumbly. Set aside. 
3. In a large mixing bowl, beat butter, sugar and vanilla together until pale and creamy.  Add egg, beat briefly until combined, then scrape down the sides of the bowl.
4. In a separate bowl, sift together the plain flour, baking powder, cinnamon and salt. Add half of the flour mixture, along with all the milk and slowly mix together on a low speed.
5. Add the remaining flour mixture and the yogurt and continue to mix until smooth and creamy. The batter will be quite thick – that’s fine!
6. Pour the cake batter into your prepared tin and scatter cinnamon crumb all over the top. Bake cake for approximately 40 minutes or until a skewer inserted into the middle of the cake comes out clean.
7. Leave to cool for 10 minutes before gently removing from the tin and leaving to cool completely on a wire rack. To serve, dust with icing sugar.