I put this on MFP, but for those of you not on there:
1 cup unsweetened vanilla almond milk (30cal - Silk PureAlmond)
2 teaspoons sugar free chocolate syrup (5cal - Great Value/Store brand)
1 teaspoon calorie free sweetener (I used Truvia)
Heat almond milk in microwave for 1:15; stir in chocolate syrup and sweetener and voila! You have hot chocolate!
Of course, you van adjust the amount of sweetener to your liking. But this was very good and tasted like something I might would get out of a restaurant. Very rich and chocolatey and DELICIOUS!