Preheat oven to 350°F. Line 2 muffin pans with paper liners.
Thaw the blueberries in a bowl in the microwave for 10 seconds at a time until mostly defrosted. Mix with 1/4 cup flour.
Mix together remaining 1 3/4 cup flour, baking powder, baking soda, cinnamon, and salt in a medium sized bowl.
Cream together butter and sugar in the bowl of an electric mixer. Mix in the eggs one at a time. Add the vanilla and mix. Stir in zucchini. Scrape down sides of bowl as needed.
Add in the flour mixture slowly, mixing until just combined. Fold in blueberries and walnuts carefully.
Bake until golden brown and a toothpick inserted in the center of the muffins comes out clean, about 25-30 minutes.