In a medium frying pan over low heat, toast black sesame seeds until hot throughout and fragrant (approximately 10 – 12 minutes). Stir with spatula every so often so seeds do not burn. When they start to smell like hot oil and are hot to the touch, take the pan off the heat. Transfer seeds to a bowl / plate and let cool completely.
In a large mixing bowl and using hand or stand mixer set to medium-high speed, whip the heavy cream for 3-4 minutes. When the cream starts to form very soft peaks (not enough to hold its shape), add salt and the vanilla extract, and continue whipping for another 3 minutes or until medium peaks form. The trails in the cream should be visible but with slightly softened peaks. Cover and chill the whipped cream in the fridge until ready to use.
Place the cooled sesame seeds (should be more or less room temperature) into a blender or food processor and pulse, adding 1 tbsp of cold water between pulsing until they release their oil and form a thick paste (you will need roughly 3 tbsp of cold water). The texture of the paste will be coarse and grainy.
Add chilled condensed milk into blender and pulse again until fully mixed.
Take the bowl of whipped cream from refrigerator and gently fold in the black sesame mixture until thoroughly combined.
Pour ice cream mixture into loaf pan and smooth the top with the spatula. Cover with plastic wrap and chill in freezer for at least 6 hours. For softer ice cream consistency chill for 6 hours, for harder ice cream consistency, chill overnight.
Notes
This recipe calls for 9” x 5” x 3” loaf pan, however other sizes and other forms of pans (i.e. 9”x13”x2” cake pan) also work. A shallower pan will help the ice cream to cool faster. Any materials (ceramic, glass, or metal pans) will work.