Unsalted Butter (Best Option)
1:1 (1 cup butter per 1 cup coconut oil)Butter works well because it has a similar fat content and solid state at room temperature, which helps maintain the dough structure and spread during baking. The water content in butter (about 15-20%) can slightly affect the texture, making cookies a bit softer.
For best results, use unsalted butter chilled and cut into small pieces to incorporate evenly. Avoid melting the butter before mixing to preserve the dough consistency.
Compared to coconut oil, butter imparts a more familiar dairy flavor and slightly less crispness, but it enhances the overall richness and mouthfeel of sugar cookies.