Line a 9×13 baking tray with baking paper and set aside.
Using an electric mixer, mix the plain flour, salt, sugar, baking powder, milk, eggs, and vanilla essence.
Once combined, slowly stir in the melted butter.
Pour into the prepared baking pan.
Topping
In a large bowl, cream the butter, brown sugar, plain flour and cinnamon together until well combined and creamy.
Evenly drop TBSP's of this mix onto the previous batter and use a knife or skewer to marble/swirl through the cake.
Bake at 180 for 35-40 minutes or when a toothpick inserted near the center comes out nearly clean.
Glaze
In a medium bowl, mix the icing sugar, milk and vanilla essence together with a whisk. Drizzle evenly over the warm cake. Serve warm or at room temperature.
Nutritional information is an estimate and provided as a courtesy. The values may vary according to the ingredients and tools that are used. Please use your preferred nutritional calculator for more detailed information.