Get the kids involved in your Jubilee Party preparations with an easy cake that they will love to make. Ingredients100g butter or baking spread, softened, plus extra for the tin175g self-raising flour50g ground almond2 tsp baking powder4 large eggs225g caster sugar125ml full-fat Greek yogurtzest 2 lemons For the butter icing175g butter , softened350g icing sugar , sievedTo decorate300g raspberry175g blueberry MethodSTEP 1Heat oven to 180C/160C fan/gas 4. Butter and line a 30 x 20cm traybake tin with baking parchment. Measure all the sponge ingredients into a mixing bowl and mix together using an electric hand whisk until smooth. Spoon into the tin and level the surface. STEP 2Bake for 25-30 mins until lightly golden and the top of the cake springs back when pressed with your finger, and the sides of the sponge are shrinking away from the sides of the tin. Carefully lift the sponge out of the tin, then transfer to a wire rack to cool. Remove the baking parchment. STEP 3To make the icing, tip the butter into a bowl and whisk using an electric hand whisk until light and fluffy. Add half the icing sugar and whisk again until incorporated. Add the remaining sugar and whisk again until smooth. Spread the icing over the top of the cold cake. STEP 4To decorate, place a double row of raspberries across the centre and down the length of the cake to make a cross. Next, place a single row diagonally from each corner to the middle. Now fill in the empty spaces with blueberries. Cut into squares to serve.