Combine the cream, coffee grinds, cardamom pods, salt and cinnamon in a saucepan over medium heat. Bring the mixture to a boil, stirring once, then turn off the heat and let the flavor steep into the cream. After 20 minutes, strain the cream through a very fine mesh sieve to remove all the grinds. Pour the mixture into another saucepan (or the same one, cleaned of grinds) and heat over medium heat.
While the cream is heating, whisk together the condensed milk, egg yolks and vanilla paste in large bowl. Very slowly and gradually whisk in the heated cream (starting with just a few drops) until combined, whisking well to mix. Press a piece of plastic wrap over the bowl, pressing down against the cream. Refrigerate for at least 4 hours or even overnight.
Once the custard is cold, add it to your ice cream maker and churn according to the directions. I used my kitchenaid mixer and churn for 20 to 25 minutes. Pour the ice cream into a freezer safe container and freeze for at least 6 hours.