Pre-heat oven to 350 degrees and liberally grease a muffin tray - or line with muffin liners.
In a small bowl mix flour, baking soda, and salt.
In a large bowl whisk the sourdough discard with maple syrup, eggs, butter, vanilla. Be sure to whisk it well so that everything is incorporated, otherwise it'll cause streaks in the muffins.
In another small bowl add the blueberries and a tablespoon of flour and gently mix to coat the blueberries. This will prevent your berries from all sinking to the bottom of the muffins.
Add flour mixture to the starter mixture and mix well. Gently fold in blueberries and spoon batter into muffin tins.
Bake for 20-25 minutes, testing with a toothpick to make sure it comes out clean.
Let rest in pan for 5 minutes until removing to finish cooling on a cooling rack.
Enjoy!
Notes
No unsalted butter? No problem. You can substitute salted butter for unsalted butter. For every half cup of salted butter for unsalted, just cut the salt by 1/4 teaspoon.Store loosely wrapped at room temperature for a few days, in an airtight container in the fridge for a week, or in a freezer for up to 3 months.