Fill a large pot with water and place a sous vide immersion cooker into the water. Set temperature to 170 degrees F (77 degrees C) according to manufacturer’s directions.
Combine eggs, cottage cheese, heavy cream, and salt in a blender; mix until thoroughly blended, 15 to 20 seconds.
Spray mason jars with cooking spray. Divide egg mixture between each jar. Screw on the lids until just barely tightened. Do not over-tighten as the jars can burst in the hot water.
Submerge mason jars into the water bath and set timer for 55 minutes. When timer is up, remove jars to a cooling rack. If serving immediately, run a knife along the outer edge and invert onto a plate; you can also eat directly from the jar. Let any remaining jars cool, then refrigerate for up to 1 week.