Blueberry Purée:

Add berries to the bowl of a food processor and purée until smooth. If necessary, add 1-2 tablespoons of water to get the blades moving.

Pass purée through a fine mesh strainer to remove the seeds. Set aside.

Hot Chocolate:

In a medium saucepan, warm the milk over low heat until steaming. Do not boil.

Add the chopped dark chocolate, stirring gently until completely melted.

Remove from heat. Whisk in the blueberry purée and blueberry simple syrup.

Pour into mugs and garnish with shaved dark chocolate, cocoa powder, blueberry marshmallows, or crushed freeze-dried blueberries. Serve immediately.