6 tablespoons unsalted butter, melted
3/4 teaspoon salt
1/2 cup canola oil
1 large egg
2 vanilla beans, seeds scraped and reserved, or 4 teaspoons vanilla extract
2 cups (10 ounces) all-purpose flour
1 teaspoon cream of tartar
3/4 teaspoon baking powder
3/4 teaspoon baking soda
1/2 cup granulated sugar, for rolling
- In a large bowl, combine the granulated sugar, melted butter and salt. Stir in the oil, egg and vanilla bean seeds or extract until combined.
- Add the flour, cream of tartar, baking powder, and baking soda, stirring until just combined. Do not overmix.
- Portion into small dough balls, cover, and chill or freeze for several hours or overnight.
- When ready to bake, preheat oven to 375 degrees F. Line baking sheets with parchment paper. Roll dough balls in 1/2 cup granulated sugar and evenly space on baking sheets. Bake, one sheet at a time, until edges are light golden brown and middles are no longer shiny or raw.
- Let cool for several minutes then remove cookies to wire rack to cool completely.
- When cool, spread a layer of cookie butter on the bottom of half the cookies then sandwich with the other half.