In a large bowl, whisk together the heavy cream, sweetened condensed milk, instant coffee granules, and vanilla extract until well combined.
Pour the mixture into a freezer-safe container, cover, and freeze for at least 6 hours, or preferably overnight.
Let the ice cream sit at room temperature for about 10-15 minutes before scooping and serving.
Notes
For a stronger coffee flavor, use 1 1/2 teaspoons of instant coffee granules. You can also add chocolate chips, nuts, or other mix-ins to customize your ice cream.