To make the sugar-free sweet cream, combine the Splenda, vanilla extract, and half-and-half in a small bowl. Stir until the Splenda is completely dissolved. This makes enough sweet cream for approximately 24 servings.

To make the Dirty Diet Coke, fill a tall glass about 3/4 full with ice. Add the Diet Coke and coconut syrup and stir gently with a bar spoon to combine. Top with 2 teaspoons of sweet cream and garnish with a lime wedge. Serve immediately.