Take a microwave-safe bowl and mix the peanut butter, marshmallows, maple syrup and cook for 30 seconds, then stir, cook another 30 seconds and stir, if the marshmallows are not melted then cook an additional 30 seconds and stir until melted. Let cool for a few minutes.
Now add ¼ cup vegan milk and vanilla extract and stir. Then add the oats and Krispies, mix until incorporated. Add ½ cup or more if you want vegan chocolate chips and stir, these will melt a bit which is fine.
Take an 8x8 and put parchment paper on it. Then press the granola mixture evenly into the pan. Now stick in the fridge for an hour or longer to harden. Cut into squares and serve. These are best stored in the fridge.