Preheat the oven to 375°F (190°C). Line 2 baking sheets with parchment paper or silicone baking mats.
In a small bowl, combine 1 tablespoon of flaxseed meal with 3 tablespoons of room temperature water. Set aside for 10–15 minutes to thicken.
In a medium bowl, sift the flour, ground cinnamon, baking powder, baking soda, and salt if using. Set aside.
Cream the vegan butter and brown sugar for about 2 minutes on medium speed using an electric hand mixer or stand mixer. It will become light and fluffy. Do not over whip.
Add the vanilla extract, plant milk, and flax egg to the butter and sugar, and mix on low until just blended.
Gradually add the dry ingredients a little at a time to the wet butter mixture, mixing on low just until combined. Fold in the oats, cranberries, and almonds with a rubber spatula by hand or on low with your mixer. Do not overmix.
Refrigerate the dough for 30 minutes. This step is optional but I find it produces the best results.
Scoop about 1 heaping tablespoon of dough, form it into a ball, and place it on the prepared baking sheets. Then repeat the process leaving 2 inches of space between each cookie. Gently flatten each cookie.
Bake the cookies for 12-14 minutes, until the edges and bottoms are lightly browned. If you bake more than one sheet at a time I suggest you rotate the pans halfway through the baking time.
When done, let cookies sit on baking sheets for about 5 minutes, then transfer to a wire cooling rack.
Store in an airtight container for up to 5 days at room temperature or in the freezer for up to 3 months.