Preheat oven to 160 Fan/ 180 Celsius/ 350 Fahrenheit/ gas 4.
Grease baking dish and line with greaseproof paper if necessary.
Add dry ingredients to a mixing bowl.Mix.
Add wet ingredients.Mix to a smooth batter.
Scoop the cake batter into the baking dish. A spatula is amazing as it helps scrape all the batter off the bowl.
Place baking dish on the middle shelf of the oven.
Bake for 25-30 minutes depending on your oven. Cake is ready when risen, lightly golden and a knife inserted comes out clean.
Leave the cake for about 20 minutes and then carefully remove from the tin. Or simply leave in the tin to cool. It will be fine.Carefully peel away the baking paper..
Once cool finish the sponge by adding the decoration.
Jam and coconut topping:
Whip your jam with a spoon to loosen it up and make it easier to spread. Spread over your cake.
Sprinkle coconut over the jam to cover.
Slice into 12 pieces.
Store jam sponge in a covered airtight container for up to 5 days in a cool, dry place. The container can also be placed in the fridge.
Un-decorated sponge can be frozen, well wrapped, for 3-4 months. Defrost at room temperature, with wrappings removed. Once at room temperature toppings can be added.
For an iced topping with sprinkles: Sieve about 12 tablespoons of icing sugar and mix with a few drops of water at a time until the desired consistency. Spread over your sponge. Scatter sprinkles over. If only decorating half the traybake with icing just use about 6 tablespoons of icing sugar.
If your icing is too thin just add some more icing sugar and mix until its how you like it.
For icing that is too thick add tiny drops of water and mix.
For a lemon traybake, you could add some grated lemon zest to the sponge mix. Use lemon juice to prepare the icing instead of the water. Decorate with sprinkles or more lemon zest.