In a mixing bowl, pour in the heavy whipping cream. Using a hand mixer or a whisk, whip the cream until it forms soft peaks. This should take about 3-5 minutes. Be careful not to over-whip.
In a separate small bowl, dissolve the instant coffee granules in a tablespoon of hot water until fully dissolved.
In another bowl, combine the mascarpone cheese and powdered sugar. Mix well until smooth and creamy.
Add the dissolved coffee mixture and vanilla extract to the mascarpone mixture. Stir until well combined.
Gently fold the whipped cream into the mascarpone mixture, being careful not to deflate the whipped cream.
Transfer the Tiramisu Dip to a serving dish and dust the top with unsweetened cocoa powder. Chill in the refrigerator for at least 30 minutes before serving.