For the Chocolate Syrup:
- 1/2 cup sugar
- 1 tablespoon light corn syrup
- 2/3 cup unsweetened, good quality Dutch-processed cocoa powder, such as Ghirardelli or Valrhona
- 1 teaspoon pure vanilla extract
For the milkshake:
- 1/2 cup whole milk
- 2 tablespoons malt powder
- 11 ounces premium vanilla ice cream (about 1 3/4 packed cups)
For the chocolate syrup, bring 1 cup water, the sugar and the corn syrup to a boil in a small saucepan over high heat. Whisk in the cocoa powder and cook until the mixture is slightly thickened, about 2 minutes. Remove from the heat and whisk in the vanilla. Transfer to a bowl and let cool to room temperature. Use 1/4 cup for the milkshake, store the remaining covered in the refrigerator for up to 1 week.
For the milkshake, combine milk, chocolate syrup and malt powder in a blender and blend for 5 seconds. Add the ice cream and blend until smooth, about 10 seconds. Serve immediately.