In a 6-qt. electric pressure cooker, combine the first 7 ingredients. Lock lid; close pressure-release valve. Adjust to pressure-cook on high for 3 minutes. Let pressure release naturally for 5 minutes; quick-release any remaining pressure, Mash apples with a potato masher or use an immersion blender until blended. Whisk in peanut butter until apple mixture is smooth. Cool to room temperature. Store in airtight container in the refrigerator.