In a medium skillet over medium heat, toast the oats until lightly browned and fragrant, about 5 minutes, stirring occasionally.Cool the oats slightly, then combine the oats and oat milk in a medium-small container with a lid.Refrigerate for 4 hours, or overnight, to soften the oats. In a blender, combine the soaked oats and oat milk, frozen banana slices, almond butter, cinnamon, vanilla, and salt, plus the pea protein powder and medjool date, if using.Pulse, then blend until smooth. If you would like a thinner shake, simply add a splash of oat milk.Stir in the chocolate chips, then serve.