Special equipment: Eight 6-inch-long lollipop or popsicle sticks
For the stirrers: Line a small baking sheet with wax or parchment paper. Place the chocolate in a small bowl over a pan of barely simmering water. Stir until the chocolate has melted and the mixture is smooth. Insert a lollipop stick into each marshmallow. Dip the marshmallows into the chocolate, allowing any excess chocolate to drip back into the bowl. Place on the prepared baking sheet and refrigerate until the chocolate has set, 20 minutes.
For the hot chocolate: Whisk together the almond milk, cinnamon and nutmeg in a 5-quart saucepan. Bring to just below a boil over medium-high heat. Remove the pan from the heat and add the white chocolate and agave. Stir constantly until the chocolate has melted and the mixture is smooth, 2 minutes. Keep warm over low heat until ready to serve.
Pour the hot chocolate into mugs and stir with the marshmallow stirrers.