Place the milk chocolate and unsalted butter into a saucepan over low to medium heat. Stir gently until fully melted and combined, taking care not to overheat.

Add the mini marshmallows to the melted chocolate and butter mixture. Stir continuously until the marshmallows are fully melted and incorporated.

Pour the Rice Krispies into a large mixing bowl. Pour over the melted marshmallow and chocolate mixture, stirring thoroughly until all the cereal is evenly coated.

Let the mixture cool slightly to make it easier to handle.

Lightly dampen your hands to prevent sticking. Using a tablespoon, scoop equal amounts of the mixture and roll each into a ball shaped like a small pudding.

Place the formed puddings on a baking tray lined with baking parchment, and chill in the refrigerator for 30 minutes.

Melt the white chocolate in a heatproof bowl over simmering water, stirring until smooth.

Transfer melted white chocolate to a piping bag or freezer bag and set aside to cool slightly.

Color the sugarpaste with the food color gels. Shape the green sugarpaste into holly leaves and the red sugarpaste into small balls to resemble berries.

Remove the chilled Rice Krispie puddings from the fridge and drizzle the melted white chocolate over the top of each pudding.

Attach the sugarpaste holly leaves and berries on top to finish the decorations.