Polka Dot Icing Cake with Strawberry & Rhubarb

Grease and line three 15cm or 18cm (will result in slightly thinner layers) round cake tins and preheat oven to 180°C (fan forced).

Sift flour, baking powder, and salt together into a medium bowl, set aside. Place butter and 1 1/2 cups sugar in a large mixing bowl and beat with an electric mixer on high speed until pale and fluffy, at least 5 minutes.

Reduce speed to medium-low; mix in egg, milk, and vanilla. Reduce speed to low; gradually mix in flour mixture until just combined.

Split mixture between the three prepared tins and smooth tops with a spatula. Arrange strawberries on top of batter, cut sides down and as close together as possible. Sprinkle remaining 2 tablespoons sugar over berries.

Bake cakes for 10 minutes. Reduce oven temperature to 160 degrees. Bake until cakes are golden brown and firm to the touch, and a skewer inserted into a non-strawberry part of the cake comes out clean, about 40-50 mins but timing will vary depending on your tin size (if on top and bottom rack, switch cakes between racks halfway through, baking). Let cool in tin on a wire rack, then turn out. Can be stored in an airtight container for a day or so before icing.

Place rhubarb, sugar, lemon and ginger in a medium saucepan. Stir over medium heat until sugar dissolved. Reduce heat slightly and simmer until rhubarb is very soft and sugar syrup is slightly thickened, about 5-10 minutes. Set aside to cool to room temp then store in an airtight container in the fridge for several days, until ready to be mixed into filling.

Remove butter from fridge 30 mins before starting and chop into small cubes. In a large mixing bowl, beat butter on high with an electric mixer until smooth and fluffy.

Reduce speed to medium-low and gradually add icing sugar until combined, add vanilla then increase speed to high and beat until very pale and fluffy. Gently fold rhubarb mixture into the icing (this may cause the icing to curdle slightly, it is easier to avoid if the rhubarb is not too cold). The icing should be smooth and easily spreadable, but stiff enough to hold its shape.

To assemble cake; remove cake layers from the fridge and use a long shape knife (preferably serrated) to carefully trim the tops of the cake to ensure they are level. Flip your cake layers upside down before assembling.

Place one layer on your cake stand and use an offset spatula to spread a thick layer of rhubarb icing over the top of the cake. Repeat with remaining cake and more icing.

Crumb coat cake with remaining rhubarb icing and then chill for about half an hour and prepare rainbow icing.

Place butter in a large mixing bowl and beat on high with an electric mixer until smooth.

With the mixer on low, gradually add icing sugar, milk and vanilla until combined, then beat on high until pale and fluffy. You can add more milk or icing sugar to achieve the right texture of icing. You want it to be stiff enough to hold its shape but soft enough to pipe.

Use an offset spatula to cover your crumb coated cake in a layer of white icing. Regularly run your spatula under hot water to achieve a smoother finish.

Split the remaining icing into small bowls and add food colouring of your choice. Place each in separate piping bags with a narrow round tip, or use small ziplock bags with a tiny hole in one corner snipped off.

Carefully pipe colour dots all over the surface of your cake. Keep cake chilled until about 30 mins before serving, then remove from the fridge to allow it to come back to room temperature. Cake can be iced the night before serving.