Preheat your oven to 350°F (175°C). This ensures that your bars bake evenly.
Line a 9x9-inch baking dish with parchment paper, allowing some overhang for easy removal later. Lightly grease the parchment with a bit of cooking spray or coconut oil.
In a large mixing bowl, whisk together the 2 eggs, 1 cup of peanut butter, ¾ cup of pure maple syrup, and 1 tsp of vanilla extract until smooth and well combined.
To the wet mixture, add 1 ½ cups of rolled oats, 1 tsp of baking soda, ½ tsp of ground cinnamon, and ½ tsp of sea salt. Stir until everything is just combined. If you’re using chocolate chips, fold them into the mixture now.
Pour the cookie bar mixture into the prepared baking dish. Use a spatula to spread it evenly, making sure it reaches all corners of the dish.
Place the baking dish in the preheated oven and bake for 20-25 minutes, or until the edges turn golden brown and a toothpick inserted in the center comes out clean.
Once baked, remove the dish from the oven and let it cool in the pan for about 10 minutes. Use the parchment paper to lift the bars out of the dish and place them on a wire rack to cool completely. Once cool, slice into squares or rectangles.
