In a separate large bowl, add sugar, whole milk, eggs, melted and slightly cooled butter, avocado oil, and vanilla extract. Whisk together until combined. The butter may appear to re-harden as you mix, that’s okay.

Add dry ingredients to wet ingredients and stir together until just combined.

Dust your blueberries cornstarch or arrowroot powder (if using) and fold in your blueberries to the batter.

If using liners, arrange paper liners in the muffin pan. Fill muffin cups about three-quarters of the way.

Let the batter rest in the muffin pan for 5-10 minutes (resting the batter is not mandatory but you will get a better rise). Bake for 12-18 minutes or until a toothpick comes out clean or with loose crumbs (not wet batter) when inserted in the center of a muffin. For a slightly crunchy crust, let the edges brown slightly.

Once they are done, let the muffins cool for 3-5 minutes before transferring onto a cooling rack