Coat the inside of 4 6-ounce ramekins with cooking spray. Combine all ingredients in a medium bowl and whisk until the mixture is well blended.
Divide the mixture equally between the ramekins and cover each ramekin tightly with foil. Place 1/2 cup of water into the cooker.
Place a trivet and steamer basket or cooking rack into the cooker. Place the ramekins in the steamer basket or on the cooking rack.
Close and lock the lid of the cooker and turn the pressure regulator knob to PRESSURE. Pressure cook on HIGH for 23 minutes.
When the cooking time is completed, use the natural release method. Once the pressure is released, remove the foil and place the ramekins on a cooling rack.
Once they cool down, refrigerate for at least 2 hours before serving.