Celebration piñata cake

Name: Celebration piñata cake
Prep time: 3 h
Cook time: 2 h
Total time: 5 h
Cuisine: American
Ingredients: 500g butter , softened; 500g golden caster sugar; 8 large eggs , beaten; 500g self-raising flour; 2 tsp lemon extract; zest 2 lemons; 175g butter , softened; 500g icing sugar , sifted; 2 tbsp whole milk; zest 1 lemon and juice of 2 (from the lemons above); 200g lemon curd; 200g butter , softened; 200g golden caster sugar; 4 large eggs , beaten; 200g self-raising flour; 1 tsp vanilla extract; 100g butter , softened; 300g icing sugar; 3 tbsp whole milk; 1 ½ tbsp freeze-dried strawberry or raspberry powder (see tip); 100g icing sugar , mixed with a drop of water to make a runny icing for glue, plus extra icing sugar for dusting; 2kg ready-made fondant icing; selection of food colouring pastes (we used blue, pink, orange, lilac, mint green and yellow); sweets, such as Smarties (about 12 tubes), to fill the cake; 4 cake dowels; white pearlescent balls or silver balls; candles