Alright, let’s get started! First, grab your butter and oil, and cream them together with both sugars. This is an important step because you want the mixture to be light and fluffy—it sets the stage for that perfect cookie texture. I’ve made the mistake of under-creaming before, and let me tell you, the cookies ended up flat and a little dense. So take your time here! Once it’s all mixed, beat in the eggs and vanilla until everything’s nice and smooth.

In a separate bowl, whisk together the flour, baking soda, and cream of tartar. Then, gradually add the dry ingredients to your butter mixture. It’s super important not to overmix at this point. If you keep beating the dough, your cookies might turn out tough instead of soft. Just mix until the flour disappears, and you’re good to go.

Next, drop spoonfuls of dough onto your prepared baking sheets. I like to use a rounded teaspoon, but if you prefer larger cookies, you can go bigger—just adjust the bake time. Pop them in the oven at 375°F and bake for 8-11 minutes. Keep an eye on them around the 8-minute mark. You want the edges to be just lightly golden while the centers stay soft.