To create the flax egg, mix 1 tablespoon of ground flaxseed with 2.5 tablespoons of water in a small bowl. Let it sit for about 5-10 minutes until it becomes gel-like.
Preheat your oven to 350°F (175°C). This ensures that your blondies bake evenly.
In a large mixing bowl, whisk together the all-purpose flour, baking soda, and salt until well combined.
In another bowl, beat the vegan butter, white sugar, brown sugar, and molasses (if using) until creamy.
Stir in the prepared flax egg and vanilla extract into the butter-sugar mixture until well blended.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined. Be careful not to overmix!
Gently fold in the vegan chocolate chips until evenly dispersed throughout the batter.
Pour the batter into a lined 9x9-inch baking pan, spreading it evenly. Bake for 20-25 minutes or until a toothpick inserted in the center comes out with a few moist crumbs.
Allow the blondies to cool in the pan for about 10 minutes before transferring them to a wire rack. Once fully cooled, cut them into squares and enjoy!