Pre-heat oven to 350°F.
Grease a jumbo muffin pan 6 muffins, with butter, this includes the top of the pan.
Sift together the flour, salt and baking powder and set aside.
In the bowl of a stand mixer, with the whisk attachment in place, on high speed, whisk together the eggs, sugar, and vanilla extract until foamy and slightly stiffened.
In a measuring cup with a spout, mix together the melted butter and vegetable oil.
Slowly add the oil and butter mixture to the egg mixture in a slow stream as the mixer continues to whisk.
Using a measuring cup, add 2 tablespoons of apple cider vinegar and add evaporated milk until it reaches one cup.
Add this soured milk slowly to the mixing bowl, continuing to mix but at a reduced speed.
Fold in the dry ingredients, by hand with a rubber spatula, being careful not to over mix.
Don't worry about lumps in the batter, they are fine.
When the dry ingredients are almost incorporated, gently fold in the blueberries.
Spoon batter into a well-greased jumbo muffin tins until 2/3 full.
If you like, sprinkle about a teaspoon each of blueberries and turbinado sugar over the top of each muffin before baking.
Bake for about 35 – 40 minutes or until a wooden toothpick inserted into the center of a muffin comes out clean.
