1 flax egg (1 tablespoon ground flax + 3 tablespoons warm water. Mix and let sit for 5 minutes)
1 stick softened salted butter
3/4cup white sugar
2 teaspoons vanilla extract
2cups all purpose flour
1 teaspoon cream of tartar
1/4 teaspoon salt
Instructions
Preheat your oven to 350 degrees F and line a baking sheet with parchment paper
In a large bowl make the flax egg by mixing 1 tablespoon ground flax seed with 3 tablespoons warm water and letting it sit for 5 minutes until "jelled"
After 5 minutes, add the softened butter, sugar, and vanilla extract to the bowl. Use a hand mixer on medium speed to cream the wet ingredients until pale in color
Next, add the flour, cream of tartar and salt and mix on low speed just until fully combined
Lightly dust a piece of parchment paper with flour and dump out your sugar cookie dough. Use a rolling pin to roll it out to 1/4 inch thick
Use your favorite cookie cutters to cut out the rolled dough, making sure to reroll the scraps
Place cut-out cookies onto your parchment lined baking sheet and bake for 7-8 minutes until the edges are very lightly brown or even pale
Carefully pull the baking sheet out of the oven and let the cookies cool on it for 5 minutes before transferring to a wire cooling rack to cool completely
Decorate and enjoy!
Notes
Make sure your butter isn't too soft
Let the flax egg sit for 5 minutes until it has "jelled" before adding the other ingredients
Don't overmix the dough or you'll end up with tough cookies
Bake on parchment paper or a silicone mat to prevent sticking
The bottom of the cookie should look very lightly golden brown or even still pale
Let them cool completely before decorating with any sort of icing