Preheat the oven to 375F. Prepare a 9 inch baking dish by spraying with cooking spray.
To a large mixing bowl add milk, maple syrup, vanilla extract, eggs, ground cinnamon, ground nutmeg, ground ginger, melted butter and salt. Whisk the wet ingredients until the eggs are combined.
Then, add the dry ingredients to the wet ingredient - baking powder, oats and lentils. Use a wooden spoon and stir to combine fully.
Finally, stir in the grated carrots and half of the chopped walnuts or chopped pecans.
Pour the entire oat mixture into the greased baking dish and top with the rest of the chopped walnuts or chopped pecans. Bake for 35-45 minutes or until the oats have set and are starting to turn golden brown. Let sit for 5 minutes before serving topped with vanilla or plain Greek yogurt, maple syrup and/or another sprinkle of cinnamon. Top with 1/2 cup Greek yogurt for over 20g protein per serving!
Optional - Make the maple cream cheese glaze to serve with the bake oatmeal by stirring together the softened cream cheese, plain Greek yogurt, maple syrup and vanilla extract. You can simply blend using a mixing spoon in a bowl or blend with a hand blender or hand mixer.