Combine flaxseed meal and water in a small bowl to create a flax egg. Set aside for 10-12 min, stirring at the midway mark, and maybe once more to help the flax absorb the water. It should be thick, somewhat gel-like, and not watery.
Whisk all dry ingredients in a large bowl and set aside (flour, cocoa powder, baking powder, baking soda, salt).
In a medium bowl whisk together the wet ingredients with the flax egg until combined (melted butter, sugar, milk, and vanilla)
Pour the wet ingredients into the bowl of dry ingredients (scrape everything out). Using a spatula, stir and fold until the dough is combined, making sure to scrape any dry powder at the bottom of the bowl (the dough will look like a very thick, sticky batter at first—this is normal. It will firm up as it chills). Wrap the dough in cling wrap and place in the fridge for 3 hours. Chilling will make it easy to handle and yield evenly-shaped cookies.
Preheat the oven to 350 °F (177 °C). Take the dough out and let it rest at room temp for 10 minutes (not near the oven). Line an extra-large baking sheet with parchment paper (or two standard-sized sheets). Prep two small bowls for sugar coating - one with powdered sugar and one with cane sugar,
Scoop out 1.5 tablespoons of dough and place it on the baking sheet. Continue until all the dough is scooped (A medium-sized cookie scoop #50 works well for this).
Now, using your hands, roll each piece of dough into a smooth ball (if dough is sticking, lightlyspray your hands with cooking oil). Now, dip the ball into the cane sugar to lightly coat all sides, then immediately dip it into the powdered sugar to generously coat all sides. Place each piece back on the baking sheet about 2 inches apart. Continue until all of the pieces are coated.
Place in the oven for 10-12 minutes until they have spread, are crackled, and are slightly set around the edges. They will look undercooked, but that’s normal, and they will continue to cook on the baking sheet out of the oven (don’t leave them in the oven too long). Let them sit on the baking sheet for 5-10 minutes, then place them on a cooling rack for at least 10 more minutes. Enjoy!
Notes
Flaxseed Meal - If using whole flaxseeds, grind them first (using a coffee grinder) and measure after grinding. No flax? Substitute ½ cup (120g) of applesauce and omit the water and the non-dairy milk. Whisk the applesauce with the melted butter, sugar, and vanilla, then follow the recipe as written. The cookies will be slightly puffier with different cracks but still delicious!
Vegan Butter - I used Miyoko’s, but any non-dairy butter works. You can use unsalted, but I felt the taste was better with the salted variety. If using unsalted, add ¼ teaspoon salt. You can also use a neutral oil, using the same method, but expect a slightly fudgier, thinner cookie. The powdered sugar seems to fade faster with oil, so it's best served within 6–8 hours.
All-Purpose Flour - For best results, I recommend weighing your ingredients. If you’re using measuring cups, the next best method is 'spoon and level': first give the flour a quick stir in the container, then spoon it into the measuring cup without packing or tapping, and lightly sweep off the excess with a knife. Avoid scooping directly from the container, as this can add too much flour and affect the final texture. Measure all other ingredients as accurately as possible using proper measuring cups and spoons.
Granulated Sugar Coating - Don’t skip this! It helps create defined cracks and slows the powdered sugar from fading. Be generous with the powdered sugar for that stark white crinkle look.
Baking Sheet - If using two standard baking sheets instead of one extra-large, bake one batch at a time. If you only have one standard sheet, keep half the dough in the fridge while the first batch bakes, then let the pan cool completely before reusing.
See the post above for extra tips, FAQs, and step-by-step photos.