In a blender, combine the milk, heavy cream, chocolate syrup, cocoa powder, powdered sugar, vanilla extract, and ice.
Blend on high until smooth and creamy, ensuring all ingredients are well combined.
Taste the mixture and adjust sweetness if desired by adding more powdered sugar or chocolate syrup.
Pour the frozen hot chocolate into glasses and top generously with whipped cream.
Garnish with chocolate shavings or mini marshmallows for an extra treat.
Serve immediately and enjoy your refreshing drink!