Step 1

Preheat the oven to 375°F. Line two baking sheets with parchment paper and set them aside.

Step 2

In the bowl of a standing mixer, beat together butter, vegetable oil, granulated sugar, and powdered sugar.

Step 3

Add the eggs and vanilla and beat for 2 minutes longer, scraping down the sides of the bowl as needed.

Step 4

Mix together flour, baking soda, and cream of tartar in a separate bowl.

Step 5

With the mixer running on low speed, add the flour mixture a couple of spoonfuls at a time until the dough is evenly combined.

Step 6

Use a cookie dough scoop to drop spoonfuls of the dough onto prepared baking sheets. Bake for 7 to 8 minutes until just lightly golden brown on the bottom edges.

Step 7

Transfer baked cookies to cooling racks.