Step 1

Preheat the oven to 425º Fahrenheit.

Step 2

Melt unsalted butter in a large liquid measuring cup or small bowl. Add vegetable oil, buttermilk, egg, sugar, vanilla extract and sourdough discard. Whisk to combine.Note: Any neutral-flavored oil can be substituted - liquid coconut or melted butter would work well.

Step 3

In a mixing bowl, whisk together the all purpose flour, baking powder, cornstarch and salt. Add the blueberries and mix together until blueberries are coated in flour mixture.

Step 4

Add the liquid ingredients to the flour/blueberry mixture and stir gently a few times until thoroughly moistened. A few streaks of flour are okay!

Step 5

Spray a 12 cup muffin tin or cut square pieces of parchment paper to fit the holes of your muffin tin. Scoop muffin batter into the muffin tins, filling the tins about 3/4 of the way full. You will have some leftover batter, enough for about 6 more muffins after baking the first 12.

Step 6

Sprinkle 1-2 Tablespoons of granulated sugar on top of the muffins before baking.

Step 7

Bake muffins for 5 minutes at 425 degrees. Then reduce the temperature to 350 degrees and bake for 18-20 more minutes. If you fill the muffin tins less full, they may bake a little faster. Check that muffins are done by inserting a toothpick into the center of one and making sure it comes out clean (there may be some melted blueberry). Pull them out of the oven and let muffins rest for about 5 minutes in the pan.

Step 8

Pre-heat the oven to 425℉ again. Take the baked muffins out of the pan and place on a cooling rack. Fill the muffin tin with the remaining muffin batter. Bake according to the same directions. Remove muffins to a cooling rack and enjoy!