In a large bowl, combine brown sugar, softened butter, vegetable oil, molasses, egg, and vanilla and beat until smooth and thoroughly combined.
In a separate bowl, whisk together dry ingredients. Add the dry ingredients slowly to the sugar and butter mixture, mixing thoroughly in a stand mixer or with a sturdy wooden spoon (it will be thick!).
Put the dough into a container with a cover and chill for at least three hours.
When the dough is sufficiently chilled, preheat the oven to 375 degrees. Lightly grease a cookie sheet or use a silicone mat. Put a few tablespoons of granulated sugar onto a plate. Roll the cookies into small balls, about 1" in diameter, and roll the balls in the granulated sugar before placing on the cookie sheet about 2"-3" apart. Bake the cookies for 9 minutes. Allow them to cool on the cookie sheet before moving to a cooling rack, then store in an airtight container.