Preheat the oven to 350°F.
In a large bowl, stir butter with sugar until light. And then, add oil, eggs and vanilla gradually.
Stir in 2 cups of flour and baking powder until well blended.
Turn out onto floured surface and knead in remaining flour. And then, knead until moderately soft dough but not sticky.
Use plastic wrap to cover the dough and leave it for 20 minutes.
Break off pieces of dough and roll on a floured surface into small snakes, about 1/2 inches wide by 4 inches long.
Knot dough pieces, or shape into a S. Place onto ungreased baking sheet, spacing each 2 inches apart.
Place into the preheated oven and bake it for 10 minutes until lightly browned.
Take cookies out from the oven and remove cookies from baking sheet by a metal spatula.
Let it cool on rack completely and keep into tightly covered container.