Place 4 heavy pint glasses in the freezer to chill for 30 minutes.
Add the ice cream, milk, ice cubes, bourbon and 4 tbsp of the chocolate syrup to a powerful blender.
Blend until smooth.
(A good milkshake should be eaten with a spoon, so if the mixture seems too thin, add another .25 to .5 cup ice cream and blend again.).
Divide evenly among the prepared glasses and top each with .5 tbsp of the remaining chocolate syrup.
Simple Chocolate Syrup:
- .25 cup unsweetened dark cocoa powder (such as Valrhona)
- .5 cup water
- 1 cup sugar
- .25 tsp salt
Whisk together the cocoa powder and water in a medium saucepan over medium heat until fully dissolved. Whisk in the sugar and increase the heat to medium-high. Boil the mixture for about 3 minutes, then reduce the heat to low and simmer for another 1 to 2 minutes. Remove from the heat and stir in the salt. Let cool to room temperature and store tightly covered in the refrigerator for up to 3 weeks.
Recipe adapted from liquor.com