Preheat the oven to 180°C or 160°C fan-forced and line a 23x33cm (9x13 inch) rectangular baking tray with cooking oil spray and baking paper. Make sure you line the sides of the baking pan with the paper all the way up as the cake will rise and the topping has a tendency to stick to the pan.

Start by making the separate components of the cake. To make the vanilla cake, add the flour, baking powder, bicarbonate of soda and salt to a bowl and whisk to combine.

In a large mixing bowl, add the white sugar, canola oil and vanilla and whisk to combine. Add the white vinegar to the milk and then add half to the bowl with the sugar and mix.

Add in half the flour mixture, whisking to combine before adding in the remaining milk followed by the remaining flour and whisk together until the batter just comes together. Set aside while you make the filling and topping.

To make the filling, mix together the brown sugar and ground cinnamon until well combined and set aside.

To make the topping, add the dairy free butter, brown sugar, plain flour and cinnamon and mix together using your hands to rub the butter into the flour and sugar until the consistency is like wet sand.

Assemble the cake. Pour half of the cake batter into the prepared baking tray. Sprinkle over the filling mixture evenly. Pour the remaining batter over the top.

Sprinkle the topping evenly over the top of the cake, right to the edges. Place the cake into the oven and bake for 30-40 minutes or until a skewer inserted into the centre of the cake comes out clean.

Let the cake cool completely before making the glaze by whisking together the icing sugar and water and drizzling over the top. Slice into squares and enjoy!