In a large mixing bowl, combine the active sourdough starter, all-purpose flour, whole wheat flour, milk, vegetable oil, honey (or maple syrup), egg, and vanilla extract. Mix until smooth.

In a separate bowl, whisk together the baking soda and salt. Gradually add this dry mixture to the wet ingredients, stirring gently until just combined.

Gently fold in the blueberries, ensuring they are evenly distributed without breaking them apart.

Preheat your oven to 375°F (190°C). Line a muffin tin with paper liners or grease it with cooking spray.

Spoon the muffin batter into the prepared muffin tin, filling each cup about 2/3 full.

Bake in the preheated oven for 18-22 minutes, or until golden brown and a toothpick inserted into the center comes out clean.

Let the muffins cool in the tin for about 5 minutes, then transfer them to a wire rack to cool completely.