In 2021, Billie Eilish shared her favorite recipe for vegan peanut butter chocolate chip cookies on Instagram. The simple recipe includes brown sugar, peanut butter, oat flour, baking soda, salt, vanilla extract, almond milk, and chocolate chips. Eilish revealed her pantry secret of using Costco’s Kirkland Signature Organic Peanut Butter and explained that the cookies are vegan and gluten-free, with oat flour made by blending rolled oats until they form a fine powder.

Eilish, a longtime vegan, created a vegan milk chocolate bar tied to her Happier Than Ever album and chopped pieces of it into the cookie dough for added creaminess. Fans can customize the cookies with their favorite vegan chocolate, whether it be dark or semi-sweet. With cookie-baking season in full swing, Eilish's recipe provides a cozy and celebrity-approved treat for the holidays.