Vegan Butter:Different vegan butters will spread differently during baking. I have had success using Country Crock, Earth Balance, and Violife plant-based butter sticks (not spread). Vegan butter can be replaced with softened coconut oil, but they will be slightly more dry. I recommend using refined coconut oil so there is no coconut flavor.
Chocolate Chips:I prefer my cookies to be loaded with chocolate chips, but if you like slightly less, use only 1 cup of chocolate instead of 1 1/2 cups. I also recommend using a mixture of chocolate chips and a chopped chocolate bar for a more varied chocolate flavor in each cookie.
Other Substitutions:The sugar can be swapped for coconut sugar, but the cookies will be darker and color and more dry. I have not tested this cookie with any flour substitutions, but I imagine a gluten-free all-purpose blend would work well!