Preheat the oven to 350°F (175°C) and line a 9x9-inch baking pan with parchment paper.
In a mixing bowl, combine 2 cups rolled oats, 1 cup brown sugar, and 1/2 teaspoon baking soda. Mix well.
Pour in 1/2 cup melted vegan butter (or coconut oil) and 1 tablespoon vanilla extract. Mix until the ingredients are fully incorporated and the texture becomes crumbly.
Press two-thirds of the oat mixture into the bottom of the prepared pan, packing it firmly to create a smooth, even layer.
Spread 1 cup vegan caramel sauce over the oat base, making sure it’s evenly distributed. If you’re adding chocolate chips, sprinkle them over the caramel at this point.
Crumble the remaining oat mixture over the caramel layer, covering it as evenly as possible. Add any optional toppings like chopped nuts.
Place the pan in the oven and bake for 25–30 minutes or until the top is golden brown and the caramel is bubbling.
Let the bars cool entirely in the pan before removing them. For cleaner cuts, you can refrigerate them for about 30 minutes before slicing them into squares.