Preheat oven: Preheat your oven to 350 degrees Fahrenheit (175 degrees Celsius).
Mix butter: Add softened vegan butter, light brown sugar, and vanilla extract to a large mixing bowl. Then, using your handheld mixer, beat until the sugar and vanilla are whipped into the butter, about 2 minutes.
½ cup vegan butter, ⅔ cup light brown sugar, 1 teaspoon vanilla extract
Add dry ingredients: Add flour, cinnamon, baking soda, and salt to the mixing bowl. Mix until well combined, mixture should be soft but not runny.
¾ cup all purpose flour, 1 teaspoon cinnamon, ½ teaspoon baking soda, ¼ teaspoon salt
Add oats and chocolate: Next, add the rolled oats and chocolate chips to the bowl and mix until well combined with the other ingredient mixture. The final cookie batter should be thick and somewhat wet; it should not be dry and crumbly. If your batter is on the dry side, add a small amount of plant-based milk (about 1-2 tablespoons) to get to desired consistency (see photo steps in recipe post step four, as an example).
1 ½ cups rolled oats, ½ cup vegan chocolate chips, 2 tablespoons plant-based milk
Add cookie dough to baking sheet: Scoop 1-2 tablespoons of cookie batter for each cookie onto a lined baking sheet. For larger and chewier cookies, use 2 tablespoons of batter (this will make about 6-8 cookies). For a thinner and crunchier cookie, use 1 tablespoon and press the batter down with a spatula before baking.
Bake cookies: Place the baking sheet in the oven to bake for 10-11 minutes. For chewier, softer cookies, bake for only 10 minutes; the cookies may not look done when you remove them from the oven, but leave them on the baking sheet for 2 minutes and they will firm up but remain soft. For firmer cookies, cook for 12-13 minutes. Remove cookies to a cooling rack and let cool before eating.