Preheat the oven to 350 degrees F and line two baking sheets with parchment paper or silicone liners.
Mix the ground flaxseed and water in a small bowl and set aside to make your flax egg.
In a large bowl using a handheld mixer or a stand mixer with the paddle attachment, beat the softened vegan butter, brown sugar and granulated sugar for 1-2 minutes until creamy.
Mix in the flax egg, vanilla and molasses, scraping the sides of the bowl as needed.
Stop the mixer and add the flour, oats, baking soda, cinnamon and salt. Turn the mixer on low speed and mix until just combined. Stir in the raisins until fully incorporated.
Roll about 1.5-2 tablespoons of dough at a time into balls and place onto the prepared baking sheets, leaving a little room between each one. Slightly flatten each one; they will continue to spread out as they bake.
Bake for 12-14 minutes, until the tops of the cookies are set and the edges are golden brown.
Let cool on the cookie sheet for 5 minutes, then transfer to a cooling rack. The cookies will firm up as they cool. Enjoy!
Cookies will keep at room temperature for 3-4 days in a covered container, or up to a week in the refrigerator. They also freeze well.