Malted Milk Piñata Cake

Name: Malted Milk Piñata Cake
Ingredients: 120g (1/2 cup) butter, plus extra for greasing; 125g (1/2 cup) caster sugar; 250g (1 1/8 cups) soft light brown sugar; 300g (2 1/3 cups) all-purpose flour; 3 tsp baking powder; 2 tbsp malted milk powder; 1/2 tsp salt; 300ml (1 1/4 cups) whole milk; 3 eggs; 1 tsp vanilla bean paste; 50ml (1/4 cups) whole milk; 150g (2/3 cup) unsalted butter, softened; 350g (2 3/4 cups) icing sugar; Approximately 300g milk bottle sweets (ideally the floury kind, they are less sticky); Colored paper straws