01 - Preheat the oven to 175°C. Line a 20 cm square baking pan with parchment paper or grease thoroughly.
02 - In a large mixing bowl, mix together the rolled oats and salt until evenly distributed.
03 - Add the mashed banana, water, sweetener of choice, neutral oil or nut butter (or extra water), and vanilla extract to the dry mixture. Stir until fully combined.
04 - If desired, gently fold in chocolate chips, chopped nuts, dried fruit, or coconut flakes.
05 - Transfer the mixture into the prepared pan. Distribute it evenly and sprinkle optional toppings over the surface if using.
06 - Bake for 20 minutes. With the oven door closed, turn off the heat and let the bars sit in the oven for an additional 5 minutes.
07 - Remove the pan from the oven and allow the oatmeal bars to cool completely before slicing into individual servings.
08 - Store leftover bars in an airtight container in the refrigerator for up to 4 days, or freeze for up to 2 months.