Whisk 1 cup Greek yogurt, cooled coffee, 2 tablespoons maple syrup, 1 teaspoon vanilla, and salt in a medium bowl until completely smooth.
Whisk in the chia seeds for 30 seconds. Let the mixture stand for 5 minutes, then whisk again to break up any clumps.
Cover and refrigerate for at least 4 hours or overnight, until thick. Stir well. If needed, loosen with 1 to 2 tablespoons of coffee or milk.
Stir the remaining 1/2 cup Greek yogurt with 1 teaspoon maple syrup and 1/4 teaspoon vanilla.
Divide the coffee chia pudding between 2 jars. Spoon or layer the vanilla yogurt topping over the pudding.
Dust with unsweetened cocoa powder just before serving. Enjoy cold for breakfast, a snack, or dessert.